# Let's talk about lega vaporizer unit



## rookie2531

Can you link it?


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## RayMarler

I'm assuming that this is the item.

http://www.blueskybeesupply.com/hot-air-oxalic-acid-vaporizer/


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## Oldtimer

hex0rz said:


> Per the owners manual, it looks like the required dosage amount is much smaller per hive. Only one quarter a gram per hive. A 15 second treatment...
> 
> The hopper holds 50 grams. That's a potential 200 hives per hopper full! 50 minutes to treat that many hives.


Regardless what the owners manual says I don't think 1/4 gram per hive will be enough, I dose at 2 grams per hive (double deep) and still have to do several treatments to get the mites. No negative effects on the bees that can be noticed at that level.


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## zhiv9

Here it is on the mfg site including the instructions. 

http://www.legaitaly.com/en/catalog...atore-professionale-ad-aria-calda-220v-detail 

I purchased the unit last season. The instructions have changed since I purchased it - the recommended temperature settings have been reduced. After using it last fall, I had some doubts about 15 seconds and found myself treating for 15 seconds or until there was visible vapour coming out of all cracks etc. I used it as a final cleanup when the hives were broodless (when wrapping for winter) instead of OA dribble. It would have been nice to do a side-by-side comparison of it vs OA dribble, but I just didn't have time.


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## hex0rz

Zhiv9, thanks for posting the link. That's where I got my information from.

So with the recommend 15second treatment interval, what are you noticing? Lackluster performance, or accurately stated results?

Are the statements from the manual up to par per your experience?


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## zhiv9

Oldtimer said:


> Regardless what the owners manual says I don't think 1/4 gram per hive will be enough, I dose at 2 grams per hive (double deep) and still have to do several treatments to get the mites. No negative effects on the bees that can be noticed at that level.


You may be right, but I do think there is difference between forcing the vapour into the hive and letting it rise passively. In cold climates forcing the warm vapour into the hive will loosen up the cluster and help ensure more bees are exposed.


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## zhiv9

hex0rz said:


> Zhiv9, thanks for posting the link. That's where I got my information from.
> 
> So with the recommend 15second treatment interval, what are you noticing? Lackluster performance, or accurately stated results?
> 
> Are the statements from the manual up to par per your experience?


As I stated above, I haven't properly evaluated the performance. After treating a hundred hives with it, I felt that 15 seconds was fine for solid bottom boards and tighter fitting equipment, but leaky equipment of SBB's needed longer.

The manual doesn't really make a lot statements or claims. They recommend treating when the colony is broodless, which is sound for OA in general since it doesn't kill mites in brood.


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## Oldtimer

zhiv9 said:


> You may be right, but I do think there is difference between forcing the vapour into the hive and letting it rise passively. In cold climates forcing the warm vapour into the hive will loosen up the cluster and help ensure more bees are exposed.


Well maybe. My climate is not particularly cold but even so you won't break the cluster in 15 seconds. Here is a video I made of doing my hives you can see the time used is longer, the weather is warm, and even so I am not certain of full penetration. Click to make it play, some versions of IE won't play this video, if not you may have to try Chrome or something.I posted this before so apologies to those who have seen it.


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## hex0rz

Hey mister! I remember that video now. I didn't realize it was you that had it. So realistically, what is 50 grams treating? What are the realistic expectations? Have you done mite drops or any other method to monitor the efficacy of the device?

Also, can you by chance give an ID measurement for the inlet side of the device so I can get an idea of what the heat gun heat shield probe size has to be? Slightly worried it'll only work with certain heat guns.


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## WBVC

I have used it and quite like it. A lot of vapour comes out in a hurry when the OA is hot enough to liquefy. You can see the vapour seeping out cracks at the top of the hive within moments of pointing it within the entrance opening. Super easy and quick to use.


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## BernhardHeuvel

I like it very much, too. I use 220 degree Celsius when vaporizing with this unit. I preheat it for 15 minutes. I do 50-100 hives with one load. I reckon 0.5 g is enough. There was a huge field trial in Germany, where mite kill occured with 0.5 g. The 2.0 g is just to make sure, the user doesn't burn the half of it. Bee damage happened with 5.0 g oxalic acid per vaporizing.

I even do less than 15 seconds. It is important to get the device running properly first. It has to smoke like hell. White vapor. You need to play with the temperatures of the heat gun. The hive has to smoke for about a minute after you removed the device. So you pull the gun out, hive continues to smoke. 

It is super quick and easy. Have not counted mites before&after, but from what I've seen, it pretty much wipes out the mites. 

When brood is present in summer, you need to vaporize every 3 days, five times in a row. Check mite population after that, and do another round of necessary. Bees don't get hurt much or at all. A friend experimented to see when the bees get hurt by multiple vaporizing. He treated as much as 25 times and couldn't see any visible damage. The hives did winter just fine.


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## Oldtimer

Bernhard do you still have that video of you using it? That was awesome I would love to see again if you could post.

Hex0rz I haven't done mite counts sorry but have looked afterwards & seen plenty of dead ones on the front door. Not very scientific I know. 

Have been doing around 25 hives from a 50 gram fill, or 2 grams a hive, but if Bernhard says 1/2 a gram is enough then I'll take his word. Just a question Bernhard, is that one deep or two?

Re the measurement, I have one heat gun that doesn't fit and two that do, but the difference is so small it is beyond the technology I have to measure it. You will probably have to take the unit to your hardware store and select one that fits, most do.


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## BernhardHeuvel

No, deleted it. But I have one video where I show the device and the heat gun.





https://www.youtube.com/watch?v=IdaJ1jWpIPc

The gun I use is: Steinel 348212 heat gun HL 2010E


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## BernhardHeuvel

Oldtimer said:


> Just a question Bernhard, is that one deep or two?


I have either types. I simply dip the pipe into the front entrance, let it blow the smoke inside and when it is coming out of all cracks and openings of the hive, I go to the next one. The hive has to smoke for a minute or so, after you removed the device. The hive stands there and smokes. 

The main trick is, that the mite's feet catch the crystals, where it builds up and makes the mite drop down to the floor board (or through the bottom screen). For this to happen, the vapor has to circulate for some time inside the hive. So one has to observe how long the vapor stays in his hives.


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## BernhardHeuvel

The mite has some sticky pads (empodium) that look like this: (my own microscope pictures)



















Detail of the sticky pad at the end of the mite's foot:









Note that there is an open channel going from the pad up into the leg. That channel is open constantly and provides moisture of the mite's body fluid to the pad, so it stays sticky.

A beekeeper I know, Gerhard Brüning, made some impressive pictures of the mites after an oxalic acid treatment: 









His description in German: http://www.varroamilbe.ch/bericht3.pdf

It seems that the vaporized oxalic crystals condense where it is moist, and that is at the sticky pads of the mites. All the pads have a buildup of oxalic acid crystals and the mites drop off the bees. 

Those crystals disappear after about 2 hours and the mites are even able to crawl back up upon a bee. But: it seems the oxalic acids dilutes into the mite through that open channel right into the mite where it causes damage to the inner organs. So there are two effects: the immediate effect is the dropping (preferably through a screen bottom board out of the hive) and the second effect is the destroying of the inner organs of the mites. From the drop I'd guess that'll be one to three days after the treatment, probably there are longterm effects, too. 

Bees don't get damaged much, although they too have a sticky pad at their feet. But there is a difference: bees can close that channel between the pad and the foot. There is a ring-like structure that can close down that channel. It is most probable - but not proven yet - that this is why bees don't get hurt much by the oxalic acid vapor.

Anyway, for us it is important to make the vapor circulating inside the hive for long enough, to make it condense at the mite's sticky pads. I reckon, dosage doesn't really matter much other than providing enough crystals to build up with type of vaporizer you have. The varrox vaporizer has been tested intensively and was found to be very effective. Other devices were not half as good. Temperature and other parameters will play into it. If you burn the oxalic acid and not vaporize it, there will be no buildup of crystals, just smoke.


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## m_pchelari

Hi, Bernhard

Can you tell the make and model of your microscope, please. Very good pictures. Is it digital microscope. I bought this microscope for nosema counts but the quality is not so good for that purpose.
http://www.celestron.com/browse-shop/microscopes/digital-microscopes/microspin-2-mp-digital-microscope


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## BernhardHeuvel

> With sublimation, varroa mortality was high, 81%, even at the lowest dose .56 g, and higher still at the three higher doses. However, the post hoc tests showed that these differences among doses were not statistically significant. Overall, the trickling method was the least effective and sublimation the most effective in terms of dose mortality. *The sublimation method gave high mite mortality at all doses used.* Dose differences were significant when the lowest subli- mation dose was compared to the three highest doses combined (F = 12.89, p = .001).


extracted from: http://www.tandfonline.com/doi/pdf/10.1080/00218839.2015.1106777

Hasan Al Toufailia, Luciano Scandian & Francis L W Ratnieks (2015) *Towards integrated control of varroa: 2)comparing application methods and doses of oxalic acid on the mortality of phoretic Varroa destructor mites and their honey bee hosts*, Journal of Apicultural Research, 54:2, 108-120, DOI: 10.1080/00218839.2015.1106777


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## BernhardHeuvel

m_pchelari said:


> Can you tell the make and model of your microscope, please.


Yes, it is a digital microscope. It is that one here: http://www.mueller-optronic.com/Mic...xpert-Trino-180-CAM-310::550.html?language=en


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## yukonjack

Wow. Great stuff Bernhard. Thank you!


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## hex0rz

I think thats the best material proof I've seen on the mechanism of oxalic acid treatment!

Thanks for that bit there, Bernard!

Everyone else, good stuff as well!


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## yotebuster1200

BernhardHeuvel said:


> Yes, it is a digital microscope. It is that one here: http://www.mueller-optronic.com/Mic...xpert-Trino-180-CAM-310::550.html?language=en


Would that be considered a sterio microscope? Seems to be a good one.


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## Harley Craig

That's a good use for a water flow meter


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## hex0rz

Yet I can't seem to find the same housing they use....


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## Harley Craig

hex0rz said:


> Yet I can't seem to find the same housing they use....



its probably a small manufacturer in another country.


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## hex0rz

I don't know plumbing, but unless it's kind of specifically made for this application by a plumbing manufacturer, I don't understand why any pipe going through a meter would have such a large reduction in size from inlet to outlet.


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## soarwitheagles

Thank you Bernard for sharing such clear researched results, awesome pictures, and clear explanation on how the OA kills the mites.


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## blueskybeesupply

Orders for the Lega hot air vaporizers will be shipping next week. We have some on the water now and some being air-freighted in. These things are awesome. As of now, we have plenty coming in, beyond pre-orders. See listing for more info and videos.


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## hex0rz

AHEM!

The time has come! I FINALLY received my package for the LEGA vaporizer unit! I'm very excited to put this device into use and start killing mites! I never thought I could be so excited over killing such a bug!

I have also received an e-mail from blue sky stating that some of the recommendations of the heat guns are not working as well as the steinel unit. I myself have a wagner brand heat gun. I guess there is a problem with blow back from the unit not fitting as tightly. I have not gotten the unit attached to the gun yet, so I shall see if there is any remedy to it.

I wanted to take a moment and post some pictures of the unit and begin with the design and eventually the functionality and efficacy of the unit. I have 2 nucs to still pick up and wont begin treatments until after they are installed. My thoughts were to install homemade sticky boards to take pre-treatments drop counts and then post-treatment drop counts for each treatment done.

I will be conducting this test on a total of 8 colonies. I'll use 1 as a control and treat them after the mite treatment testing. But first, lets start with pictures of the unit! This is strictly the unit itself. A board was included with some foam adhered to it to block the entrance when applying the vapor. I will not but using the board as my entrances will be circular entrances.








NOTICE! Its very revelating to figure out, that this unit is INDEED essentially, a water meter housing, pipe reducer and a copper pipe! Should I be disappointed over this? Maybe... I definitely stand corrected to the thought that it wasnt a housing. Regardless, I paid someone to come up with a simple device that I couldn't think of. The few perks to the addition of the basic unit is that it had a molded plastic outer case, and probably a metal cup that they have pressed.

This device really could be replicated easily, but I would never advocate selling it out of respect to the inventor and possible patent infringement. Well, there you have it boys and girls! Next up, real world testing! More to come!


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## sakhoney

bet I could score an old water meter from a buddy at the water dept. More to come


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## zhiv9

I bought a Steinel gun for mine and the fit wasn't tight enough. I ended up shimming it with some aluminum foil to tighten it up. I noticed that the new ones have a set screw to improve the fit. Just a heads up that I turned my Steinel on high to burn out some left over OA when I was done treating and eventually the unit got hot enough to to start to melt the plastic casing.


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## Oldtimer

sakhoney said:


> bet I could score an old water meter from a buddy at the water dept. More to come


It's been tried, good luck with that. Thought you were TF?


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## hex0rz

Oldtimer said:


> It's been tried, good luck with that. Thought you were TF?


Hey OT, I don't recall, what was the temp to set the heat gun at to sublimate the OA?


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## hex0rz

A small update. I've began test fitting the wagner heat gun with the OA unit and find that yes indeed, there is a blowback occuring. My first remedy is using foil tape to the tip and wrapping it until the fitment is tight. Then I've rotated the unit as if to thread the device to the tip. Applying a certain amount of the tape has allowed a very nice fit and the blowback is currently a minimum.

We'll see how this works, and if the tape burns then I may try and source some glass tape from a stove place to take up slack and seal without causing any problems. I've got some extra laying around but I'll try the foil tape first. So far, I'm impressed with the idea and cant wait to start treating! I may actually have the most successful beekeeping year, yet! lol...


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## Oldtimer

Re the temperature, for me anyway I have to somewhat disregard what the digital readout is and wind the temperature up pretty hot to get things started, then once it's blowing out plenty OA vapor wind the temperature down till it's running OK, play it by ear rather than what the gauge says.

With my heat gun it is a tight fit there is no blowback. But I took the LEGA to the store and found one that fitted, they do exist. I see they have added a screw to yours so they must have run into problems with other sized heat guns, mine does not have that.


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## My-smokepole

I would try aluminum tape for furnace duck work.


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## Oldtimer

My-smokepole said:


> aluminum tape for furnace duck work.


Would that be furnace *duct* work?


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## sakhoney

Old timer - I have been so far - never hurts to have a back up plan if needed agree? And if I decide to treat I don't want it to take a month to do the job. That's why I'm looking into this


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## My-smokepole

Any more up date on this unit? Witch Wagner heat gun? Just there cheap one. Model #


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## red

I bought both the lega vaporizer and the steinal heat gun. The gun fits to loose to stay in the vaporizer by itself and when I tighten the set screw it pushes the gun off the unit. Not really what I expected after spending around 400.00 on the product. I guess tomorrow I will be spending a little time at the machine shop.


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## zhiv9

red said:


> I bought both the lega vaporizer and the steinal heat gun. The gun fits to loose to stay in the vaporizer by itself and when I tighten the set screw it pushes the gun off the unit. Not really what I expected after spending around 400.00 on the product. I guess tomorrow I will be spending a little time at the machine shop.


I had the same issue, except that they hadn't added the set screw yet. Just shim between the gun and the Lega unit with some aluminum foil to tighten the fit. I also was disappointed given the cost of the unit, thought I don't think it is intentional - it isn't like they are manufacturing this, they are putting together some off the shelf pieces.


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## zhiv9

My-smokepole said:


> Any more up date on this unit? Witch Wagner heat gun? Just there cheap one. Model #


You need the OA to vaporize, but not breakdown. A gun with temperature control is required.


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## yousowise

What is the outside diameter of the copper tube that goes in the hive?


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## hex0rz

I'll update this more tomorrow, when I'm not working my night job. So no one thinks I'm neglecting this thread...


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## zhiv9

yousowise said:


> What is the outside diameter of the copper tube that goes in the hive?


roughly 1/2" - probably whatever the closest standard metric copper pipe size given that they are from Italy


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## yousowise

My entrances are smaller than 1/2 inch. In your opinion if the end of the copper tube was flattened a bit would it still operate? My thought is if the copper tube heats up it should prevent the oa from crystalizing and clogging up the reduced outflow? Not sure how hot it gets though.


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## hex0rz

Alright, so I have a video of the vaporizer in action! I only needed to check a few hives for laying queens so I had some time to record me treating them. I was not able to get any drop boards installed to do counts and measure efficacy, but I think that will matter more later in August when there is a larger mite buildup anyways.

If anyone has questions or comments, feel free! I dont have a video editor to show certain things on the video, so if you see something point it out and I'll do my best to explain.


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## yotebuster1200

youtube says the video is private!


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## hex0rz

yotebuster1200 said:


> youtube says the video is private!


HMM? I set it to public... I even logged out and viewed it as a lurker and was able to view it. Try again, as I released the link to the video before it was fully uploaded.


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## yotebuster1200

Well I just tried it again and it worked.


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## Oldtimer

Nice! Glad you got it working so well! 

The big thing i noticed when I got mine was how fast it was compared to doing them with those battery operated ones that you have to reload for each hive.


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## hex0rz

Yes, I'm impressed with the speed at which this will treat a hive. The first hive in the video I was treating was longer so I could try and show the vapor coming out of the lid. Unfortunately, it doesn't look like I captured it very well.

Once I start having outyards, it'll be one of those small inverter generators and an extension cord on a reel! That will be a small, efficient way of getting those pesky mites!

In a certain part of the video, I show the unit and the heat gun. The mating is ****ed sideways. I have found out that the metal tape does not stay in place and the unit can come off the gun. It gets so hot with the pre-heat, the adhesive lets go. If I crank down the set knob, it will **** the unit sideways. If I don't hold the unit upright and let gravity keep it together it will fall apart. I have to also push the gun with the unit into the entrance to keep the mating tight.

I have come up with a couple different remedies for this:

1. On the tip of the heat gun where the set knob contacts, drill a hole large enough so the set knob will lock in the hole on the tip of the gun. This would hold it in place. I was even thinking about doing this on the opposing side as well. This heat gun will dedicated to the bees anyways...

2. Try some glass tape and see if that works to hold it in place.

Money is on having to do #1 though...

Despite not having hard numbers to prove the efficacy of the treatment, a couple nucs I had bought already had queens laying and going for a while. All I know is that after the first treatment, I saw a significant mite drop on the bottom from them. Its hard to accept that 15 seconds a hive is adequate! But thats why I bought this system!

I filled the cup in the device 3/4 way full with oa crystal initially and I'm still using that same amount to do my treatments. I think it will go a long way before needing refilled.

Also, when I preset the temperature to 1120F, if you notice, the vapor coming out is not really much like a vapor, it has a more bluish color to it. I think its actually burning instead and its smoke coming out. Then when I turn it down to 560F, it gets white and more cloudy. It may not be very clear in the video, but in person it is noticeable.


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## mmiller

I see you set the unit at 560 F. I thought I read somewhere that the setting should be in the 300s F? I tried to find where I read it, couldn't find it so I'm probably wrong. Is 560 F the recommended setting from the manufacturer?


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## hex0rz

The manufacturer doesn't give a specific temperature range in the instructions. I actually had to reference from a video that someone else did over there in Europe with theirs and read the comments section to find out what they set it to. Then I had to convert the Celsius to Fahrenheit. If I set the gun to the same temp as what oxalic acid sublimates at, 320, it won't blow vapor.


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## Oldtimer

Same thing here, if I set to the temperature it's supposed to be it doesn't make much vapor, I have to set it quite a bit higher. My suspicion is something in the set up makes it read higher than what the temperature in the chamber is on the surface of the actual oxalic acid, and it has to be wound up higher to vaporise it well.

I don't go much by what the gauge says I go by if what's coming out the nozzle looks right. It can also be tested to ensure it is actual oxalic vapor not further broken down to formic, by pointing it at the outside wall of a hive. The oxalic vapor settles and immediately crystalises into a fine layer on the surface it is pointed at, thereby showing that the vapor is indeed vaporised oxalic, and has not been overheated into something else.


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## BernhardHeuvel

Same here. I look for the vapor and how it does look like. 

The temperature in the heatgun is different from the temperature in the vaporizer is different from the temperature in front of the vaporizer. I found out, that you actually can hold your hand (with gloves on) about 10 cm/4 inches in front of your vaporizer without burning. That's why the bees won't get burned much because it cools so quickly. 

@hex: don't you close your hives when vaporizing? Also I think there was too little vapor in the hives. My hives are still "smoking" for about a minute after the treatment. Out of every crack and hole.


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## hex0rz

BernhardHeuvel said:


> @hex: don't you close your hives when vaporizing? Also I think there was too little vapor in the hives. My hives are still "smoking" for about a minute after the treatment. Out of every crack and hole.


Well, technically they are closed. 

I don't worry about them being 100% sealed. I saturate the hive like normal and move on. I still see the vapor coming out of small cracks afterwards so I know I got a dose in there. Good? I would hope so... Like pointed out earlier, by the time it disperses into the hive, the vapor has cooled enough to the point it recrystallizes and settles. This idea of leaving the hive sealed for minutes after treating is not necessary to _*me*_, IMO.

My spring buildup this year is looking ALOT better than last years. By the time the summer flow had hit, I was already stricken with PMS from I think a lack of thorough treatment from the supplier. I'm taking a prophylactic approach to the mites to ensure they stay as mite free as possible before the flow this time, so I know what condition they are in.


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## Oldtimer

Hmm, pms already, means in an expanding broodnest you'll need to stay right on it, plus keep careful watch once the flow is over also.


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## hex0rz

Oldtimer said:


> Hmm, pms already, means in an expanding broodnest you'll need to stay right on it, plus keep careful watch once the flow is over also.


Sorry OT, I was talking past tense with that. I had pms last year around this time. That's why I'm nipping any possible infestation in the rear before the flow even starts this year.


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## Oldtimer

Oops, read your post again, i totally misread it first time!

Which is a good thing, hopefully you will have a great season coming up.


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## G B

Tagging in.... Great info gang thanks much to all


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## snl

hex0rz said:


> This idea of leaving the hive sealed for minutes after treating is not necessary to _*me*_, IMO.


That's only true if you get enough OA in the hive to crystallize prior to it escaping. Those vapors you see leaving the hive are the mite killing OA crystals. If they're escaping the hive, they are doing no good. Time will tell if your technique works for you...


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## yotebuster1200

Well, we talked on this thread that the Lega vaporizer is just a water meter housing and some pipe fittings. Well bought a cheep water meter off eBay for $22 and some.pipe fittings and came up with my own. I probably have $40 in it. 

https://youtu.be/JZxdCBGIS10


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## soarwitheagles

yotebuster1200 said:


> Well, we talked on this thread that the Lega vaporizer is just a water meter housing and some pipe fittings. Well bought a cheep water meter off eBay for $22 and some.pipe fittings and came up with my own. I probably have $40 in it.
> 
> https://youtu.be/JZxdCBGIS10


Please share the link where I can purchase the Ebay water meter.

Thank you!

Soar


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## Oldtimer

Nice work votebuster.

Can you do a pic with the lid unscrewed so we can see the inside?


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## EastSideBuzz

hex0rz said:


> AHEM!
> 
> The time has come! I FINALLY received my package for the LEGA vaporizer unit! I'm very excited to put this device into use and start!


I think you can fill it with weed and get a whole room of people stoned. I live in WA so that is what the kids thought when they saw it all put together. They asked what it was after I had the heat gun attached and I said a weed gun.


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## yotebuster1200

I am going to post a thread about the assembly with pictures and everything but I will get you started. 

Here is the water meter.
http://www.ebay.com/itm/Home-Garden...553389?hash=item1ea7a3deed:g:W4QAAOSwys5WVl4L
I bought a different one that was a couple bucks cheaper (only because I didnt see this one) and I actually just ordered this one to build another one. 

Here is the cup that goes inside. 
http://www.amazon.com/Stainless-Ste...&redirect=true&ref_=oh_aui_detailpage_o03_s00

You will have to take everything out of the water meter housing. Replace it with a cup. I had to cut my cup down a little bit to get it to fit but I dont think you will have to with the other water meter housing. 

On the heat gun side you will need a female garden hose - 3/4" male pipe fitting (adapter) I found this adapter in the garden hose fitting/repair section at ace. You will also need a 3/4" pipe to 1 1/4 galvanized reducer (or 1" depending on the size of your heat gun). Put the adapter on the water meter housing and then the reducer on the adapter. This will connect you to the heat gun. ( you might have to grind a little of the threads away to make the heat gun fit tight)

On the exaust side you will need a 3/4 female garden hose - 1/2 male Pipe fitting/adapter (also found in the garden hose fitting section at ace) you connect that to a 1/2" pipe coupler and then connect that to a 1/2" 5" nipple. 

That should be all the parts you need. If you look for variable temperature heat guns on amazon you will find several of them.


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## yotebuster1200

EastSideBuzz said:


> I think you can fill it with weed and get a whole room of people stoned. I live in WA so that is what the kids thought when they saw it all put together. They asked what it was after I had the heat gun attached and I said a weed gun.


Haha. I want a video


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## Oldtimer

Wow, well if that can be done for 40 bucks and work as well as your video I think the days of those 12 volt thingys may be numbered, except for people with just 2 or 3 hives that speed does not matter!


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## mmiller

Well my Lega unit was delivered last week and yesterday I was able to treat about 150 colonies easily. The only thing keeping me from being able to do more was the drive time between yards. I'll be able to finish up the other 50 or 60 today. I'm really impressed with the speed of this unit after its heated up and running. One piece of advice is to loosen the lid when the unit is still warm cause you may not get it off when it cools and have to reheat it to get it off. 

I'll be checking some bottom boards today to see what kink of mite drop I had. 

So far I'm very impressed with how fast and easily I can treat hives in numbers but I'm unimpressed with the mating of the unit to the heat gun. It was mentioned about drilling a hole for the set screw and I'll be trying that this morning.


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## Oldtimer

Strange everyone is having problems with the fit to the heat gun, I have a heat gun purchased from Lega plus two purchased locally and it is a snug perfect fit with all of them and will not fall apart till I forceably prise them apart. 

I'm thinking that in Italy and in my country we use metric measurements but in US it's imperial, wondering if that is causing a slight mismatch?


----------



## mmiller

Oldtimer said:


> Strange everyone is having problems with the fit to the heat gun, I have a heat gun purchased from Lega plus two purchased locally and it is a snug perfect fit with all of them and will not fall apart till I forceably prise them apart.
> 
> I'm thinking that in Italy and in my country we use metric measurements but in US it's imperial, wondering if that is causing a slight mismatch?


You are probably correct in the metric measurements. I tried 4 different heat guns and had the same issue with all of them.


----------



## Bob J

I think this is awesome! The only downside I can see is having to bring a small generator to each site for power..... Of course this is not a problem if your yard is near the house....


----------



## zhiv9

Oldtimer said:


> Strange everyone is having problems with the fit to the heat gun, I have a heat gun purchased from Lega plus two purchased locally and it is a snug perfect fit with all of them and will not fall apart till I forceably prise them apart.
> 
> I'm thinking that in Italy and in my country we use metric measurements but in US it's imperial, wondering if that is causing a slight mismatch?


There isn't a metric Steinel and imperial Steinel gun. There are just different voltages. My Steinel gun as the identical body/form spec to the european version that Lega sells.

I think the the water meter base they are re-purposing probably changed slightly. If you bought the Lega earlier the fit was better. I contacted them last fall regarding the fit and they seemed surprised - since then they have tried to band-aid it with a set screw on newer models. Shimming it with a piece of aluminum foil works fine to tighten up the fit.


----------



## hex0rz

Bob J said:


> I think this is awesome! The only downside I can see is having to bring a small generator to each site for power..... Of course this is not a problem if your yard is near the house....


It's better than lugging around a battery that needs charged frequently...


----------



## hex0rz

It's not the water meter or anything like that, that is the problem. It's the iron pipe reducer they're using that is causing fitment issues. In fact, I wonder if I went to the hardware store and bought a reducer with US dimensions of that would work. Thread pitch might be a problem when screwing it into the water meter housing though.


----------



## kramerbryan

That's a nice unit Yote. Here is what I came up with for under $100 with the heat gun.


----------



## yotebuster1200

kramerbryan said:


> That's a nice unit Yote. Here is what I came up with for under $100 with the heat gun.


Very nice. That was some good thinking. I was trying to brainstorm some different ideas until I found a cheap water meter.

Did you solder or braze your copper pipe on? I tried solder but if I was doing a quick warm up it would get to hot for the solder. If I crank my heat gun to high for 30 sec to 1 min then I can turn it down and it is good to go. I let it settle in for a couple min after that and get to treating.


----------



## My-smokepole

Yotebuster you might try silver solder it has a higher melt point. But you might need a Oxsee acetylene torch


----------



## yotebuster1200

My-smokepole said:


> Yotebuster you might try silver solder it has a higher melt point. But you might need a Oxsee acetylene torch


Ya went out and bough some MAPP gas hoping it would give me enough heat but still couldnt get it to work. That is why I just ended up screwing on a 1/2 nipple and smashing it a little with a vice to make it fit in a 3/4" opening.


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## hex0rz

Very cool at what you guys have cooked up! This is the sort of thing I was hoping would gain traction. Die mites, die!


----------



## mike17l

kramerbryan said:


> That's a nice unit Yote. Here is what I came up with for under $100 with the heat gun.


Looks great. Can you provide a parts list? Is the heat gun itself part of the $100?

Thanks!!


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## kramerbryan

Yes I soldered it. I also heat it for a minute or so on high then dial back down and the solder seams fine. I was worried about the exhaust being too warm for the bees, but it seems to just warm.


----------



## kramerbryan

sorry wrong video


----------



## Flyer Jim

OK, are these diy things still working or did everyone give up on them?


----------



## LoneWolf

I made a home made vaporizer out of some copper pipe and it worked so so. I bought the Lega and have been using it for about 2 months. It works well, but the plastic melted and the blow back was bad. I sealed the Lega to my heat gun with some high temp stove pipe sealer which solved the blow back issue. I ended up removing the plastic housing and wrapped the Lega with exhaust pipe tape. That solved the problem of melting plastic. I think the biggest issue is the size of water meter used. The heat gun has an exhaust opening of 1.25", but the water meter opening is only around 5/8". That restrictions is why heat guns must be turned up higher to get the desired results. I think eventually the heat guns will have a shorter life span caused by the restriction. It does treat hives quick and easily, but I think there is room for improvement.


----------



## hex0rz

Flyer Jim said:


> OK, are these diy things still working or did everyone give up on them?


I'm still using my lega unit. No doubt about it. Its just not time to be treating right now. Been debating whether or not to make a separate thread about the units efficacy though. 



LoneWolf said:


> I made a home made vaporizer out of some copper pipe and it worked so so. I bought the Lega and have been using it for about 2 months. It works well, but the plastic melted and the blow back was bad. I sealed the Lega to my heat gun with some high temp stove pipe sealer which solved the blow back issue. I ended up removing the plastic housing and wrapped the Lega with exhaust pipe tape. That solved the problem of melting plastic. I think the biggest issue is the size of water meter used. The heat gun has an exhaust opening of 1.25", but the water meter opening is only around 5/8". That restrictions is why heat guns must be turned up higher to get the desired results. I think eventually the heat guns will have a shorter life span caused by the restriction. It does treat hives quick and easily, but I think there is room for improvement.


If you have a better idea, let's hear it. I don't have to have my gun turned up to deliver the oa. I'm sure it the gun will last a very long time.


----------



## Oldtimer

hex0rz said:


> Been debating whether or not to make a separate thread about the units efficacy though.


If you do please link here so I don't miss it.


----------



## Bob J

I made one that works ok but takes a long time to reach temperature..... Am thinking it's mainly due to the large amount of thermal mass (metal housing, copper pipe etc).... Am thinking that insulating the inside to keep the heat primarily on the oxalic or coming up with a mechanism made of high temp plastic might work better.... A high temp plastic housing would be lighter as well....


----------



## hex0rz

Oldtimer said:


> If you do please link here so I don't miss it.


That gets me, considering you have been using it much longer than I have! You of all people should know the effectiveness of it.


----------



## Oldtimer

Well I'm undecided it has not been quite as effective as I hoped although I guess I want a lot, I do have to follow up some of the hives with something else. I am genuinely interested how others find it, could be I'm doing something wrong or something that could be done better.


----------



## yotebuster1200

Oldtimer said:


> Well I'm undecided it has not been quite as effective as I hoped although I guess I want a lot, I do have to follow up some of the hives with something else. I am genuinely interested how others find it, could be I'm doing something wrong or something that could be done better.


Have you used other forms of OA in the past that you are comparing the LEGA against? Or are you talking about OA in general?


----------



## Daniel Y

Oldtimer said:


> Well maybe. My climate is not particularly cold but even so you won't break the cluster in 15 seconds. Here is a video I made of doing my hives you can see the time used is longer, the weather is warm, and even so I am not certain of full penetration. Click to make it play, some versions of IE won't play this video, if not you may have to try Chrome or something.I posted this before so apologies to those who have seen it.


The cluster would not need to break in 15 seconds. It would need to break in the time the OA is in the air. which by my observations will be hours.


----------



## Oldtimer

yotebuster1200 said:


> Have you used other forms of OA in the past that you are comparing the LEGA against? Or are you talking about OA in general?


I've messed with all the methods of applying OA including the other vaporisation methods, they have all best I can tell been roughly similarly effective provided done as per "the manual". I'm not complaining, it's a fact OA doesn't get the mites inside brood cells so on that basis have to expect less than perfect results and timing between treatments may be critical. For me, OAV via the Lega works well enough for most of the hives but there is always a few hives that at the end of the treatment schedule still have enough mites to require some more action.

All I'm asking for others feedback for is just to see what others are doing with their Lega and how it's working for them, and see if there's anything I could learn that will improve my own results.


----------



## hex0rz

The plan is to do this for the dearth starting in August. Why don't we start establishing a set of parameters and get an outline for the test so when I do it, we are all happy with the results.

My thoughts are as follows:

A drop count and sugar roll for each hive before the testing. A 15 second treatment per hive once every 5 or 7 days for a total of 3 treatments. A drop count will be done after a 24 hour period following each treatment.

No control hives as I refuse to lose any to mites for the sake of testing.

Not all my hives are of the same strength. What are we going to qualify for the test? I currently have 6 hives that are double deep and the others are trailing behind.


----------



## BernhardHeuvel

I got good results. But: schedule is most important with brood present.

3 days apart for six times in a row. 

A weekly intervall for three times will end in a disaster or at least with mixed results. Keep the schedule tighter with lots of brood present. If you have little brood in the summer dearth that could be different.


----------



## hex0rz

If this unit requires that kind of frequency to treat for mites, then it's a bust. No way anybody in their right mind will treat with that kind of frequency. 

The amount of time involved in treating hives and all the different out yards one may have will make a person go in the red by using this unit. 

A passive vaporizer doesn't even need that sort of intensive treatment regimen!


----------



## Bkwoodsbees

I agree with Bernhard, my oa fall treatment every 5 days 3 treatment followed by single during a brood less time in late fall ( didn't have brood less time because of warm winter ). Didn't work. Very heavy spring build up early flow , supers on and mite levels in some hives went above threshold. Caused abnormal early queen failure. My mite levels have been low last couple of years. I see I need to change timing of treatments. The mites evidently adjusted to my schedule.


----------



## My-smokepole

So what temperature are you all running your steinal heat gun..


----------



## BernhardHeuvel

hex0rz said:


> The amount of time involved in treating hives and all the different out yards one may have will make a person go in the red by using this unit.


I am not in the red so far. I have 100 hives per wintering/holding yard and treat a yard in roughly an hour. Even with all the driving between the outyards you can do enough hives per day to get it all done. I have a generator on a pickup truck, simply drive by the hives (U-shape setup), fire the generator, fill the cup up to the rim, wait ten minutes until it gets smoky and then go around and stick the gun into the entrances. Easy enough.

I wouldn't state it is the best way to treat hives, but sure it is quick and cheap. The tricky part is the brood thing. Which is the problem with all treatments, that mites hide in the brood. And they are good in doing this. 

The Italians do cage the queen into a special frame pocket on one or two frames. Within the hive. It is like a compartment made from queen excluders. So the queen is restricted to few combs. You leave her in the cage until all other brood emerged, you then remove the two combs but leave the queen and treat the now broodless hive with one treatment. To knock all the now phoretic mites down. 

Basicly a lot of Germans do the same. Without the cage thing. After the last honey harvest (July that is here) they remove all brood combs. Replaced with foundation. Bees get feed. And treated one time. 

Brood combs are collected with some bees on them (soft shake to remove most but not all bees) and brought to a seperate apiary. You stack those combs on queenright hives. Only those towers are treated during the period until all brood emerged. Bees are treated finally and used to make new hives or strenghten the other hives.

All in all a lot of work. The good thing is, bees go on fresh drawn comb into winter. This way you get out all the pesticides collected throughout the year and you also reduce the presence of viruses. Bees always seem to be stronger before and after winter when building their wintering nest completely new. Plus you reduce the use of treatments on the wintering hive, which also contributes to bee health.

Would be interesting to search for easier ways to make them broodless and thus reducing number of necessary treatments. A friend of mine heavily feeds them until the broodnests are packed with food and only little brood is left, he then treats them with vaporizing oxalic acid. 

All good and fine but I think there must be a better way to use oav, which itself is a good thing. Cheap, quick, knocks down mites, doesn't harm bees.


----------



## BernhardHeuvel

My-smokepole said:


> So what temperature are you all running your steinal heat gun..


220 degree Celsius/428 degree Fahrenheit


----------



## Brandy

After spending alllll day with my lega unit I'm now sure that the amount of feet above sea level has a lot to do with temperatures... I'm at 5500' and I have to keep above 500 degree f or I don't get any vapor... Zilch, nada, so my concern is how high a temp. is safe to be pouring that vapor into the hives???

I've also been using extension cords and I think that's part of the problem... Which generator in the 3kw category
are you all using???


----------



## hex0rz

I personally will not spend that much time to treat that intensively when doing a cost analysis will probably yield me something better. If I can do a treatment with something else, be more effective and spend less time and money doing it, you bet in doing it. 

I guess these lines can get blurred when I'm speaking as someone who is trying to make profit compared to hobbyist.

Regardless, any testing I'll do, will be with the 5 to 7 day treatment interval. If at the conclusion of the test, the mite count shows to still be high, then it'll warrant a different treatment or a different treatment schedule. 

Refer to my video posting on page 3 of what temp I set my heat gun to. I used extension cords as well and did not experience Any problems. Ensure that your cord is at least 14ga. Also maybe ensure your heat gun is working properly as well.


----------



## BernhardHeuvel

When I'm speaking as someone who actually is doing a profit and making a living from bees only, probably nothing gets blurred. Some people just try to be more organic by using softer rather than hard chemical treatments. That's not easy, for sure. 

If you want to do the easy thing, use Amitraz as anyone else in the business does.


----------



## zhiv9

OA is a useful tool in an overall IPM strategy. It is important to always be using more than one treatment type to prevent resistance. We use OA in the broodless period when wrapping the hives for winter. If there is brood we use something formic acid based (spring or late summer/early fall).


----------



## Brandy

hex now that I look at your temp. setting I see that you also have to go greater than 428 f. as Bernhard mentioned and get your vapor at 560 f. Since I'm still twice the elevation as you I can see that indeed it takes at least the 560 f. degrees I was playing with yesterday. And yes, two overwintered nuc sales will absolutely justify the cost.


----------



## Flyer Jim

I really like these vaporizers you guys are making,and am about to try one myself. I do have one question, what is the chances of setting a grass fire? Calif. is burning right now and I do not want to start another fire.


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## kramerbryan

If you set that unit down in dry grass it's going to burn. Stay away from dry vegetation.


----------



## Shearer

I have just purchased one of these units and loaded it with Oxalic acid and turned it to 280 (preset temp) and waited the 5 minutes but it didn't have vapor coming out. Should I simply wait longer before lowering the temperature to the 200 working temperature or turn it up higher initially?
thanks


----------



## BernhardHeuvel

I'd wait a little longer.


----------



## Shearer

BernhardHeuvel said:


> I'd wait a little longer.


I checked and the instructions are in Centigrade.
So I tried it at 1,120 to vaporize it and then 560 to work blowing it in the hives like a video I saw and it worked great.
Ready now to go and apply some to the hives.
thanks


----------



## Oldtimer

For me I wind the temperature well up then bring it down as the unit stats vaporising nicely.


----------



## My-smokepole

I know somewhere in the thread some one was having trouble with their Honda power inverter. Just a follow up I have a inverter wire into my truck and it work for me.


----------



## Gino45

A little late to th decide that party; however, how do you determine that a followup is needed?

I'm sorry. This was intended as a followup to Oldtimer's statement that sometimes he has to do a followup on 'some' hives.


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## Oldtimer

My method is pretty crude Gino45 because I don't mess with mite counting or whatever.

Just, a couple or more months after treatment I noticed the odd hive showing signs of mites so did a follow up treatment or several treatments. Most hives work out fine though.


----------



## Gino45

Thanks, so do you have a treatment schedule? IOW once a year, twice, 3 times?

I'm asking because I continue to have mite problems, and once a year doesn't cut it, and twice can be marginal here in our 12
month bee season.


----------



## Oldtimer

Well over here everybody including me treats twice a year, spring and fall. Pretty much because it only takes 12 months for hives to die of mites here, there is no treatment free debate here because it's just not an option. Maybe climate but more likely our bees, which come from a fairly narrow gene pool.

So I alternate various treatments to avoid resistance developing, and haven't used OA for a while now. But when I use it, it's a late fall treatment. Bees in my area have brood 365 days of the year so that can reduce the efficiency of a treatment like OA that only gets phoretic mites.


----------



## aran

@yotebuster1200 
mate did you ever put together a video on how to assemble this gadget?


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## texanbelchers

You linked to a meter on eBay that has a 1/2" connection. Do you think a 3/4" or 1" would work better?


----------



## Arnie

Hex,
Which fan setting do you use on your heat gun?


----------



## hex0rz

Arnie said:


> Hex,
> Which fan setting do you use on your heat gun?


Medium-high.


----------



## aran

I ordered the water meter...going to try collect the rest of the stuff at the hardware store to give Yote's diy model a go.
Wish me luck!


----------



## liljake83

So I just got finished doing my first yard with the lega unit I noticed some wierd things and was looking for others experience after warming it up and setting the temp to 600f it smoked really well for about 7-8 hives I could see through the site glass that the oa crystals had become liquid or so it seemed then that really good smoke went way down much less dense I finished about 10 other hives and then checked the oa when I unscrewed the top there was oa in a smoking crystalized lump no longer liquid is this normal are my temps wrong?


----------



## Oldtimer

The "good smoke" you got for the first few hives may have included a lot of water vapor, making it look more impressive. Then after that is boiled off you get to the good stuff. 

I test for this by briefly pointing the unit at the paint on the outside of a box and see what crystalises on the surface. If it's a fine powdery coat of good dry crystal I know all is well, if there is water vapor I put more into those hives till the water content is gone. There is a certain amount of guesswork involved but luckily a hive can be given quite a large overdose without any apparent harm, unlike if administering OA via a drizzle which should not be overdosed.


----------



## Beekkirk

Need some help! I'm obviously doing something wrong.

I just finished up 3 applications, 7 days apart on all my hives (120+ hives) with my lega vaporizer. Set the gun to 1100* till i get the oxalic acid to a liquid and it starts to boil, then back down to 500-600* and gas hives till i see vapors coming out the cover. Anywhere from 15-30 seconds. I dont block the entrance, just stick the gun in. 

Did some alcohol washes last night, still tons of mites. Everywhere From 10-20 mites in a 300 bee sample, 3-6% infestation even after my 3 week treatment regiment. I was hoping that i would be in the 1-2% range. I have lots of hives that I think are crashing and I believe its from my high mite load. 

So after seeing these results last night I threw a screened bottom board on the hive with 20 mites/300 bees. Pulled out my varrox battery powered vaporizer and gased this hive the way I did last year with great success on all 22 of my hives at the time. This morning, 12 hours later I pulled out the mite board and had hundreds of dead mites. 

Why isnt the lega unit performing as well as the slow varrox version?

Am I over heating the oxalic acid and created formic gas? 

I noticed the fog coming from the lega doesnt seem to be as white as the varrox, maybe this is because of the air speed from the heat gun?

I also noticed that the lega crucible is still 1/4-1/2 full of white powder where as the varrox always burns off pretty clean?

At this point im thinking of gassing all my hives again with the slow painful battery way.


----------



## Oldtimer

When I started using OAV I too did the standard 3 x's 7 day apart treatments and was not very successful. I moved to more treatments 4 to 5 days apart and it worked.


----------



## kramerbryan

Beekkirk, I noticed the same thing with my homemade lega-type unit and have gone back to the varrox. I notice that the lega's doesn't seem to be as thick of a cloud of vapor. I am wondering if it doesn't coat everything as well as varrox.


----------



## Arnie

Here's what I have noticed after a few times with the Lega:

#1. I have to have the metal cup at least 3/4 full of OA in order to get good vapors. I have 4 backyard hives I tried the Lega out the first time on. I didn't use enough OA the first time.

#2. After a few minutes at 1100 degrees F sometimes there is still no vapor coming out. Then I give the Lega a tap to get more OA in contact with the metal cup. Then the fumes start.

#3. After the vapor gets going well, lower the heat to 600 degrees F or 650. At 560 degrees the fumes are pretty thin.

#4. Keep the blower fan on high.

#5. Give the hives two shots of the vapor for 30 to 45 seconds each time. And cover the entrance with a wet towel, especially if there is a slight breeze. The fumes have a tendency to blow right back out the other side of the entrance even without a breeze. Keep the entrance closed up for a few minutes.

#6. Give the Lega a tap once in a while to keep the OA in contact with the metal cup.

I treated mine first time with the Lega and checked the bottom board. About 300 mites over two days; on the third day about 20. Then I used my OAV wand and checked the bottom board. Another 300 or more mites in one day!


Today I did it again with the Lega but I took my time to make sure the fumes got in the hives pretty good. I popped one of the hive tops and saw vapor coming from the inner cover hand hole. I thought that was a good indication that my technique has improved.

Takes a little practice.


----------



## Beekkirk

Oldtimer, Do you use the lega 4-5 days apart? 

I forgot to mention that yesterday I did 2 tests. Both on hives with 20/300 mite. One with the lega one with the varrox. 12 hours later this morning hundreds of dead mites on the varrox, only about 20 on the lega.......... So then this morning the hive that I treated with the lega I treated again with the varrox and 10 hours later a couple hundred dead mites. Its obvious that either I'm doing something wrong or the lega just doesn't work. I started to re-gas all my hives today with the varrox.


I have also noticed you have to give it a tap or two while warming it up in order to get the powder acid to fall down into the already liquid acid. Tap too hard or tip the thing over and you have created a huge mess. Get it down the copper exit tube and it cogs up bad. Just went around feeding 2:1 syrup and gassing behind me as a went with the varrox.


----------



## Arnie

Beekkirk, how long did you leave the Lega in the hive when you did your test?

I also spilled the liquid acid. Eats right through fabric. 

I gotta go read Bernhard's description of how he does it again. According to him the Lega is great. 

I hope I can get good results. Hate to spend 340 dollars on a useless tool.


----------



## Fishmaster50

I read about heating to 1100 degrees. Is that correct? At our bee meeting they said if OA heated over 380 degrees it turned to carbon monoxide and will kill your hive. That was the first I ever heard of that so I'm wondering if this is true?


----------



## Arnie

The 1100 degree setting is just to get the OA heating up faster. It never even comes close to that temperature inside the cup where the OA is.


----------



## Oldtimer

Beekkirk said:


> Oldtimer, Do you use the lega 4-5 days apart?


Yes, at 7 days apart good results were patchy.

Also, Lega recommend a hive is treated for 15 seconds. In my view this is nowhere near enough, mine get about a minute, and I don't mind putting in more than a gram a box.


----------



## Beekkirk

I usually treat for at least 20-30 seconds and as oldtimer said that might not even be enough. Ive been gassing till i see it coming out of the lid. I did a mite count today on a 5/5 nuc that I purposely tried to over gas and it still had a 3% mite load. Had I known that this lega set up would take 1 minute per hive i would have never ever bought it!

Generator ~ $300
Lega/heatgun $467
Total $767

Today I treated with extra long jumper cables off the truck in sets of 2 after feeding and pulling undrawn frames of foundation out. It was perfect timing.

What I should have originally done was

Extra long jumper cables ~$70
4 Varrox vaporizers ~$560
total ~$630

4 hives would take 4 minutes with no pre-heat time needed, no need to haul around generator, gas, maintenance. Just as fast as the lega and do alot better job. 

Ive been considering buying the vmvaporizer in the future but having second guesses especially at $3500. It may have the same issues as the lega. Maybe I can get them to send me one to demo?!?


----------



## Arnie

A minute per hive. I'll try that next. Maybe 1 1/2. Thanks OT.
If I can just get it dialed in to where it's effective I'll love it. Still faster and less hassle than those wands and battery packs. Although for the backyard the wands are fine.


----------



## jim lyon

Beekkirk said:


> I usually treat for at least 20-30 seconds and as oldtimer said that might not even be enough. Ive been gassing till i see it coming out of the lid. I did a mite count today on a 5/5 nuc that I purposely tried to over gas and it still had a 3% mite load. Had I known that this lega set up would take 1 minute per hive i would have never ever bought it!
> 
> Generator ~ $300
> Lega/heatgun $467
> Total $767
> 
> Today I treated with extra long jumper cables off the truck in sets of 2 after feeding and pulling undrawn frames of foundation out. It was perfect timing.
> 
> What I should have originally done was
> 
> Extra long jumper cables ~$70
> 4 Varrox vaporizers ~$560
> total ~$630
> 
> 4 hives would take 4 minutes with no pre-heat time needed, no need to haul around generator, gas, maintenance. Just as fast as the lega and do alot better job.
> 
> Ive been considering buying the vmvaporizer in the future but having second guesses especially at $3500. It may have the same issues as the lega. Maybe I can get them to send me one to demo?!?


Good luck with the vm vaporizer folks. I gave up after getting no response from repeated calls and e mails.


----------



## jean-marc

He is back in business after having had some legal disputes with a partner... vmVaporizer, that is.

Jean-Marc


----------



## hex0rz

Man, this is strange. Chugging away with my unit and have no problems. Mite counts are good, bee's look healthy, no dwv. Night and day difference than last year. 

Guys should refer to my video in this thread. 

One thing i noticed, first load of oa in the cup needs some reduction work. Warm it up (1120f)the first time for a few minutes so the oa isn't boiling anymore. That's all the water in the crystals.

After(560f), i get a solid chunk of crystals that i vaporize and can tell it's working better. The bees near the entrance aren't fortunate to escape my vapors and they fly out of the hive covered in white crystals. 

Remember what sublimation is... are we sublimating or vaporizing?

There is a difference.


----------



## Beekkirk

Hex, are you saying that i need to boil it till it stops boiling. Then when it turns back to that white solid, gas the hives? Ive noticed if i leave it on 1100* the whole time it boils and then turns back to to a solid alot quicker then if you heat at 1100* and back down to around 600*. The gun also throws alot more vapors once its turned back to a solid. Is this solid something other then oa?

Just did a test this morning with boiling it till it turned back to to solid and then gassed a hive with the gun left at 1100* the whole time. Will report results tonight.


----------



## hex0rz

Beekkirk said:


> Hex, are you saying that i need to boil it till it stops boiling. Then when it turns back to that white solid, gas the hives? Ive noticed if i leave it on 1100* the whole time it boils and then turns back to to a solid alot quicker then if you heat at 1100* and back down to around 600*. The gun also throws alot more vapors once its turned back to a solid. Is this solid something other then oa?
> 
> Just did a test this morning with boiling it till it turned back to to solid and then gassed a hive with the gun left at 1100* the whole time. Will report results tonight.


You are probably getting oxalic acid dihydrate. This compound contains 2 water molecules. Because of this, when you reduce it, it's gong to break down and the water is going to be released from the bonds. You need to boil that off first before the oa really does it's job. This only needs to happen when you refill the hopper. Visual on vapors looks the same so i usually look at the cup first to see what's going on before using after filling. 

You still need to turn the gun back down after boiling the water off because your still burning the oa and it's not actually vaporizing it. 

If you can, try and find oxalic acid anhydrous. This will keep you from having to deal with the water boiling issues.


----------



## Arnie

Just trying to dial in the technique.

Next I will try Bernhard's technique of letting it warm up for 15 minutes, but I'll do it at 600 degrees instead of 420. He says "It smokes like hell" so that's what I will try for.

I got a good quantity of vapor yesterday, I'm not convinced enough of the good stuff is getting into the hive. The difference in the mite kill numbers with the Lega and the wand are what concern me.

So when the wind stops howling here I will try the Bernhard warm-up technique combined with the Oldtimer one-minute timing.

Gonna kill me some mites!


----------



## Arnie

I want one of these! See that vapor? That thing rocks.
https://www.youtube.com/watch?v=yYl63Akou3E


----------



## zhiv9

I used mine yesterday to treat 125 hives and 30 nucs. I seem to be able to get it to really smoke sometimes, but not consistently. I've been setting it to 1150F/600C and waiting until it starts to blow a decent amount of vapour (but certainly not clouds) and turning it down to about 590F/310C and then getting started. I have been treating each hive for 30 seconds or until vapour is coming out the top. It seems about 5 or so hives in if I gave it good shake it would start to really blow a lot of thick vapour. Now I am thinking that I am not letting it heat up enough initially.

So far I haven't really been impressed with the efficacy (but maybe I haven't been getting enough vapour out of it). I had a yard that missed a treatment due to a move that has high mites. Counts per 100 bees on four hives were 8/8/6/3 on Sep 23. Treated with the Lega on Sep 24. Couldn't get back there again until yesterday (9days) later and counts were 8/7/9/3 - so no real change. I treated again yesterday. There was very little brood this time when I treated, so I think it should be 80+% effective. Planning to follow up this Friday.


----------



## hex0rz

I think that there has to be a technique to it. What that is, i dunno. If we could get more people involved that have used this unit before it got imported to the us, then we could probably be further ahead. 

I know OT has used it for some time, but he's just one guy. Need to see if there is more consistency to application method. Regardless, if that doesn't happen, then we will figure out ourselves in due time. 

I never did get around to formally testing the unit in August. I kick myself for that...


----------



## Beekkirk

hex0rz said:


> I never did get around to formally testing the unit in August. I kick myself for that...


I feel exactly the same way. 

zhive9- When you give it a bang when your gassing the hives and notice alot of vapor thats just from the liquid splashing out of the cup and contacting the metal.


----------



## crofter

I wonder if the variable moisture content of a person's Oxalic acid container has an effect on how much bubbling up, crusting over, collapsing etc., is changing the outcome from one person to another. I had to make the bowl of my oxalic acid vaporizer larger to keep from spillover but did not notice it when the container was fresh.

Following the thread with interest as the tray type single dose methods gets time consuming with more than a handful of hives and doing multiple treatments.


----------



## Beekkirk

crofter said:


> Following the thread with interest as the tray type single dose methods gets time consuming with more than a handful of hives and doing multiple treatments.


But so far most have found this to be the best way.... there are ways of speeding up the process like doing multiple at a time. 

Ive been playing with these ideas.

Doing 20, 40 hives all at once with the single tray style vaporizer. 
Wire them in a line, 4 feet apart, 10 trays or more. 

Generator ----i----i----i----i----i----i----i----i----i----i

Fill them with oa, slide them into the hive, rag the entrance plug into generator. 
Voltage drops, resistance, lots of power needed? I dont have a clue about electrical engineering. 

Or some sort of 4 way pallet with cheep vaporizers built into the floor. Tip hive, fill with oa, plug pallet into generator. Bang. Do a couple of pallets at a time while you are getting the next hives prepped and making inspections/bee work. 

There has got to be a cheaper way then spending $3500, soon to be $4000 with the new model coming out, plus the air compressor, on a vmvaporizer.

Id also like to stay away from the vapors more then I do now with the lega. This would be possible for my above ideas. With the lega and the vmvaporizer your constantly in the vapors. I dont put much faith in respirators.


----------



## Arnie

No way around it, this will take more than 15 seconds per hive.

I tried a couple things with the Lega today:

First I heated it up at 650 degrees with no OA in the pan. I put a digital thermometer wire in the pan and when it got to 385 I put a half teaspoon of OA in it and closed up the top. I thought it would vaporize more quickly, but it kept on boiling and smoking for over four minutes without being evaporated completely.

Next I tried to "Bernhard" it. I filled the cup halfway with OA and set it at 650 degrees. But after 15 minutes, no sign of vapor.

Cranked it up to 1100 and soon got vapor, down to 650 and continued to get vapor, but not huge clouds. To be fair, the wind was blowing pretty hard and it was cool out, so I think that cut down on the visible vapor.

The OA boiled for a long time, so I am not going to wait until the water boils off. I found that with the OA boiling I got some nice white powdery condensing of the vapor when I pointed it at a piece of wood. Lots of crystals on the sight glass and the inside of the metal shotglass OA cup.

I took a little raw white rice and tied it up in a bit of cheesecloth and popped it in the jar of OA to prevent the OA from taking on more moisture, and maybe dry it out a little. 

Tap the Lega once in a while to release more vapor. I bought a Wagner Furno 750 heat gun. Seems pretty nice, lots of temp settings. I wonder if it has enough cojones to heat the Lega up enough. 

Back to square one: Pre heat the OA, turn down the heat setting and give the hives the smoke. I think I may pre heat the Lega before I add the OA, 5 to 10 minutes on 1100. Lets see how that works. Maybe, maybe not. 

I will now try giving each hive a minute to two minutes of vapor. Pop the hive top and see how the 'smoke' is doing. Just have to be patient and be sure to get enough OA in each hive. 
All in all it's likely to be faster than filling those pans each time, inserting into the hive, blocking it all up with the towel, turn on the battery pack, wait 2 1/2 minutes, turn off the battery, wait a minute more, take the wand out and cool it, load it again........

But now that I have seen the videos of the Sublimox type vaporizers I want one.


----------



## Stephenpbird

I don't have a lega.
But I have been using OAV for a while. 
Two things I have noticed, If the bowl is at all dirty (black crud) then the OA does not vaporize fast at all. So I scrub it with a wire brush to keep it gleaming. It makes a big difference for me.
The second is placing the OA on a piece of paper in a warm oven for 10-15 minutes to get rid of the moisture. I feel it helps speed the reaction up a little but most of all it makes the OAV process more predictable as far as heat and timing goes.
I am thinking of building one of these so Thanks for the thread everyone.


----------



## Beekkirk

https://www.youtube.com/watch?v=yYl63Akou3E

Im going to try to use my lega in a similar fashion as the one in the above video and do some testing. Im going to make a custom cap for the lega that is just a simple gravity seal. No need to screw it back together. Going to try to operate it just like the video. 

I think for one reason or another, heating up a large quantity of oxalic acid does not work as effective as a single dose at a time. It may have to do with some sort of chemical breakdown or just a much longer gassing time needed. Either way I have found the Lega to be absolutely useless


----------



## camero7

> I think for one reason or another, heating up a large quantity of oxalic acid does not work as effective as a single dose at a time.


The vm vaporizer makes that statement questionable at best.


----------



## Beekkirk

The vm vaporizer I believe only treats 4x hives per load. I may be wrong but I recall reading the lega is sold on the basis that you can treat 40 hives in one pot.

I still have not been able to create crystals from the lega when pointed at an object. Is this because of the air movement? Im not sure. Did some testing

The varrox creates a ton of crystals with a peice of wood over it 1" above. A good 5" circle with 1/4" of cyrstals.

So then I got the lega up and going. Once the lega was at the point I would have start gassing the hive (boiling oa) I took the lid off and put piece of wood 1" over. This was to simulate the previous test I did with the varrox and eliminate the air dispersion from the heat gun. No crystals formed after 2 minutes.......waited a couple more minutes, nothing. Just a slight 2" circle of white haze formed.


----------



## soarwitheagles

Arnie said:


> I want one of these! See that vapor? That thing rocks.
> https://www.youtube.com/watch?v=yYl63Akou3E


Arnie,

I like the speed and effectiveness of this unit on youtube. Does anyone have any info on where to buy it?

Thanks!


----------



## Arnie

soarwitheagles said:


> Arnie,
> 
> I like the speed and effectiveness of this unit on youtube. Does anyone have any info on where to buy it?
> 
> Thanks!


Soar,

I found this:
http://www.icko-apiculture.com/en/sublimox.html?___from_store=fr

You need the Sublimox, an inverter to change 12v to 220v and likely an extension cord. Kinda pricey.

Also, this looks interesting. If you can use it with OA only, and not have to mix in Thymol I would buy it. I sent an email to the seller to find out about it.
http://www.icko-apiculture.com/en/sublimox.html?___from_store=fr

This one is cool too. No idea where to get one.
https://www.youtube.com/watch?v=-t9b0tGpyu0

I'm waiting to see what snl comes up with. He is supposed to have one ready to go in November. That will probably be our best bet.


----------



## MT204

Arnie said:


> Soar,
> 
> 
> This one is cool too. No idea where to get one.
> https://www.youtube.com/watch?v=-t9b0tGpyu0


I spent the last day building one like the one in this video. 
Hard to tell if it is home made or manufactured. 
I "test drove" the one I built and it vaporizers 3 grams in about 20 seconds. I'll post a picture when its all done.


----------



## Arnie

MT204 said:


> I spent the last day building one like the one in this video.
> Hard to tell if it is home made or manufactured.
> I "test drove" the one I built and it vaporizers 3 grams in about 20 seconds. I'll post a picture when its all done.


I wanna see that!!!


----------



## hex0rz

On the interest of keeping this thread on track, please refrain from talking about other units other than the lega. If you want to have such a discussion, please start a new thread.


----------



## jim lyon

Interesting variety of opinions on this unit. I recently purchased one and was prepared for trouble after reading this thread. Yesterday I treated about 350 hives and while I can't comment on the efficacy of the treatments I was impressed with its overall performance. It seemed to put out plenty of vapor after the initial warmup. I did roughly 20 seconds on singles and about twice that with doubles and though our equipment, overall, is pretty tight I would see vapor seeping out of any little cracks within the first 10 seconds. I used the foam block that came with the unit and it seemed to do a pretty good job of forcing the vapor into the hive.


----------



## zhiv9

It's the efficacy that I am concerned with. I have posted some results below. I have increased the treatment time to 25-30 seconds depending on much vapour the lega is blowing and how "leaky" the hive is. In general for the first treatment there was likely still a frame or two of brood. By the second treatment there might be a couple of small patches of brood. I treated for a third time yesterday and most colonies are pretty much broodless. One yard had a few SBB's and sticky boards do show a significant mite drop, but at this point the unit really isn't keeping up with the rising mite population vs declining bee population curve. I'll update with further results if I get a chance. I bought the unit because the claim was a better than 90% mite kill when broodless - that just doesn't seem to be the case.

Yard 1
Starting mite level: avg 6.4% - max 8%/min 2%
After 1 treatment: avg 9.5% - max 12%/min 2%
After 2 treatments: avg 8.2% - max 12%/min 5%

Yard 2
Starting mite level: avg 2.4% - max 3.2%/min 2%
After 1 treatment: didn't have time to test
After 2 treatments: avg 3% - max 10%/min 1%

Yard 3
Starting mite level: avg 4.9% - max 7.4%/min 3.4%
After 1 treatment: avg 6.75% - max 10.3%/min 3.3%


----------



## jim lyon

zhiv9 said:


> It's the efficacy that I am concerned with. I have posted some results below. I have increased the treatment time to 25-30 seconds depending on much vapour the lega is blowing and how "leaky" the hive is. In general for the first treatment there was likely still a frame or two of brood. By the second treatment there might be a couple of small patches of brood. I treated for a third time yesterday and most colonies are pretty much broodless. One yard had a few SBB's and sticky boards do show a significant mite drop, but at this point the unit really isn't keeping up with the rising mite population vs declining bee population curve. I'll update with further results if I get a chance. I bought the unit because the claim was a better than 90% mite kill when broodless - that just doesn't seem to be the case.
> 
> Yard 1
> Starting mite level: avg 6.4% - max 8%/min 2%
> After 1 treatment: avg 9.5% - max 12%/min 2%
> After 2 treatments: avg 8.2% - max 12%/min 5%
> 
> Yard 2
> Starting mite level: avg 2.4% - max 3.2%/min 2%
> After 1 treatment: didn't have time to test
> After 2 treatments: avg 3% - max 10%/min 1%
> 
> Yard 3
> Starting mite level: avg 4.9% - max 7.4%/min 3.4%
> After 1 treatment: avg 6.75% - max 10.3%/min 3.3%


Yes. Trying to achieve control in large populated hives mid summer with multiple treatments is one thing but if you are dealing with broodless bees late in the season I kind of question what the point of vaporizing really is. I can treat with a trickle application in about the same time and its a treatment that I have a lot of confidence with. My thinking was that a vaporization if it can be done quickly and efficiently would be ideal for large holding yard applications where it isn't convenient to open each hive.


----------



## zhiv9

jim lyon said:


> Yes. Trying to achieve control in large populated hives mid summer with multiple treatments is one thing but if you are dealing with broodless bees late in the season I kind of question what the point of vaporizing really is. I can treat with a trickle application in about the same time and its a treatment that I have a lot of confidence with. My thinking was that a vaporization if it can be done quickly and efficiently would be ideal for large holding yard applications where it isn't convenient to open each hive.


I have confidence in the trickle as well, but it is a one shot deal so I would save it until early November when I knew the colonies were broodless. I was hoping OAV would fill in between a late August early September Formic/MAQS treatment and the November trickle. I was also hoping that I could eliminate the need for the trickle as I disliked both breaking the propolis seal and splitting the boxes so late in the year. I also thought it would be easier on nuc's. I am planning on keeping up with the OAV treatments for another week or two to see if the numbers come around. As the last bit brood emerges, I should see a sharp downward turn in the mite levels if the unit is effective. If not I'll be following with a trickle when wrapping.


----------



## Beekkirk

Jim I would advise you throw some mite boards on and make sure you are actually accomplishing something. I'm chasing my tail right now retreating my hives. Lots of wasted time. Like you I thought the speed and the devise was amazing. No one has yet to post any evidence with mite washes to back up this product. I treated with the lega 3 weeks in a row in Sept. I'm now retreating with the 12v style and getting huge mite drops. I put some sbb under many of my hives. It's time consuming but it works. I've got lots of data I'm compiling, as in mite washes, and will be posting soon when I'm done with my last round of treating.


----------



## jim lyon

Beekkirk said:


> I'm now retreating with the 12v style and getting huge mite drops. I put some sbb under many of my hives. It's time consuming but it works. I've got lots of data I'm compiling, as in mite washes, and will be posting soon when I'm done with my last round of treating.


Any idea why?


----------



## zhiv9

jim lyon said:


> Any idea why?


With the spoon type vaporizers you are getting a full 2g vapourized per hive. The same may be true of the vmvaporizer with the clouds of vapour it produces. With the Lega it's a lot more variable. I'll fill up the cup and get it blowing a good amount of vapour, but it will gradually decline as the cup empties. As someone else mentioned tapping it will sometimes get the vapour really going again (I am assuming it sticks to the side of the cup or something).


----------



## jim lyon

Yes I saw some of that but when I saw any lessening of vapor that wasn't alleviated by tapping I shut down and reloaded. I was trying to understand why beekkirk felt that a straight 12 volt element might do a better job than a heat gun sublimation. Not arguing here just trying to understand if there is a fundamental difference in effectiveness between the lega system and something else.


----------



## zhiv9

jim lyon said:


> Not arguing here just trying to understand if there is a fundamental difference in effectiveness between the lega system and something else.


Me too. I have been doing a lot of washes to try to figure out its strengths and weaknesses. I originally used it based on performance assumptions that may simply not be true.


----------



## Arnie

I think the difference is the fact that the OA pulls away from the metal cup and doesn't evaporate as well.
In one of my trials with the Lega I dropped a half teaspoon of OA, into the cup already pre-heated. After 4 minutes it still had not all vaporized.

With the Varrox after 2 1/2 minutes the OA in the cup is gone, so we know all of it got into the hive in a timely manner.

With the Lega full, I noticed pretty good vapor, but still not very thick. After almost 2 minutes the vapor was just barely coming out the hole in the inner cover. With the Varrox the vapor is billowing out.

Lastly, in the trials I have done with the lega, I found that there was a fairly weak mite drop for a couple days after the treatment, then on the third day, none. On the third day I used the Varrox. Next day a large mite drop. So the kill rate has been poor so far for me.

Next time I am going to keep the temp up pretty high when doing a test. 

Not sold on this tool at all.


----------



## jim lyon

Fwiw just did another 48 double hives. Filled the cup to 90% treated each hive for about 30 seconds (usually begins seeping out of the lids in the first 10 seconds) had lots of vapor for the whole yard and just a small gray mass in the cup when I was done. Vapors still wafting from the hives for a couple minutes afterwards.


----------



## Arnie

Jim, did you pack the OA down into the cup, or just spoon it in?
What temps are you using on the heat gun?
Thanks


----------



## jim lyon

Arnie said:


> Jim, did you pack the OA down into the cup, or just spoon it in?
> What temps are you using on the heat gun?
> Thanks


Mostly going with your suggestion. 1100+ to start with then down to a little over 600 degrees. Yes, spooning it in and gently packing it. Probably doesn't make much difference but I have a pretty big generator and I'm using a heavy cord. I've been cleaning out any residue immediately after I shut it down and it seems to warm up pretty quickly. Again, not saying I really know much just relating my experiences thus far.


----------



## Beekkirk

Arnie said:


> In one of my trials with the Lega I dropped a half teaspoon of OA, into the cup already pre-heated. After 4 minutes it still had not all vaporized.
> 
> Lastly, in the trials I have done with the lega, I found that there was a fairly weak mite drop for a couple days after the treatment, then on the third day, none.
> 
> On the third day I used the Varrox. Next day a large mite drop. So the kill rate has been poor so far for me.
> 
> Next time I am going to keep the temp up pretty high when doing a test.
> 
> Not sold on this tool at all.


I have already done what you described and also what you plan on doing. It didnt work at all. It didnt mater if I left it at 1100 the whole time or 600 the whole time. Didnt mater if i dropped in 1 dose at 1100 or at 600 and treated. Just didnt work. Every test i did with the lega I would wait 24hrs and check the mite board. Almost nothing. Then I would treat with the varrox and get humongous mite drops. I have lots of data writen down to compile soon. So I know the mites were there, the lega just wasnt doing the job. I feel like I have tried using the lega every possible way. All different temps, filling the pot different amounts, adding more to the pot as it vaporizes off, purposely over gassing hives like 4 minutes. Almost no results. Use the same oxalic acid in the varrox, and bang hundreds of mites on boards that previously had nothing with the lega. 


So........

I have concluded that the hot air is the demise of this product. The vmvaporizer uses cool compressed air to move the oxalic acid away where as the lega is using heated air. Many European models only use cool air to move the vapor. 
When using the varrox, the cool surrounding air takes away the vapors. 
When using the lega, 600 air is moving the vapors away.

I think a solution to this problem is to create some sort of cap for the lega that has a second vapor outtake pipe coming out the top. The hot air will continue to come out of the original copper pipe but you will have a second pipe rigged up to the top that you use to gas the hive. The vapors would leave the devise on there own without 600 air interfering.

Im going to try and mock something up and see what happens, first by trying to create crystals on a peice of wood, then testing some hives. I have not been able to create these crystals trying many ways with the lega where as the varrox does. I think this is the biggest indicator that you are creating an effective vapor.


----------



## Brandy

BK, what type of heat gun are you using with your lega?? Sorry for your difficulties since my experiences have been good after a little trial period... I guess I'm lucky again since I've even just stirred what little is left and added new and it still warms up pretty fast... Good luck,


----------



## Beekkirk

I'm using the stenneil? Heat gun that blue sky sells


----------



## Brandy

Well I was ready to blame a cheap heat gun... But that's the same gun I have and no problems and lots of mites dropping... So hopefully you'll figure something out.... Has to be the heat/acid/vapor combination since your getting it with the varrox. Good luck


----------



## Arnie

OK.

After reading all this and getting depressed I tried another experiment. I got out one of my wands and watched the vaporization process. 
At first the OA turns to liquid, then boils. While it is boiling it gives off just a little steam.
After a while longer it begins to re-crystallize. Then it stops giving off vapor for a few moments. Then the good stuff begins. 
As it gets hotter the mess of crystals starts to smoke, good thick smoke. It disintegrates as it goes on smoking.

That made me think of something Bernhard had written. He says he warms his Lega up with the OA inside for 15 minutes, then it smokes like hell.

I tried it at the temp he recommended but nothing happened for 20 minutes; so I cranked up the temp to 1000.
Then, through the sight glass, I could see the OA start boiling.
I waited. 
After a while the steam started, then after more time the good smoke started.

I tried holding the exit tube against a piece of wood while the steam was going and then afterward while the smoke was thicker.
Much, much better white crystals! 

My hope is that I have not been waiting long enough to get through the steam stage and fully into the smoke stage.
It took about a half hour to get the good stuff. I think if I had started hotter to begin with that time would be less... maybe 20 minutes at 1000. Edit: 1000 degrees until the OA is boiling well, then another 15 to 20 minutes at 590 or so until the smokes gets thick. May have to play with it.

Also, I tried the fan at very low setting and liked it better.

So the Lega Saga continues. 

Also, another thought.

I watched many of the European videos of the fast units. The Sublimox, and those propane burners, etc.
In those videos you can sometimes hear the hiss of steam as soon as the OA hits the hot element. They are zipping through the steam stage. So maybe the key to the Lega is to wait much longer for it to get to the good smoke stage.


----------



## hex0rz

All good information! The issue at hand is that there is not enough people from across the water on here that can give us enough info for a good troubleshoot. 

Itd be helpful if OT and Bernard could chime in on this, since they have used this unit the longest. It gets me, i know OT has used this unit for quite some time but yet doesn't have problems with mites. I wonder if he could do some tests and get us numbers on his drops. 

I know my unit is working good because i treated my observation hive and did it through the entrance tube. It condensed on the tube and inside the hive at the entrance. Looks frosty not all crystallized. My wife also got a whiff of it recording me do it and she had to leave the room. It does work. 

That other factor to consider is what oxalic acid are your buying? Are you biting the right stuff?

I know at the least, we are uncovering new territory doing this here in usa. Hopefully it'll become a good thread with some good data compilation of the unit. 

Like i said before i dropped the ball and didn't do the testing i should have in August. Hopefully i can be one to add to the experiment next year.


----------



## zhiv9

hex0rz said:


> I know my unit is working good because i treated my observation hive and did it through the entrance tube. It condensed on the tube and inside the hive at the entrance. Looks frosty not all crystallized. My wife also got a whiff of it recording me do it and she had to leave the room. It does work.


It's really no indication of actual effectiveness - washes indicate that



hex0rz said:


> That other factor to consider is what oxalic acid are your buying? Are you biting the right stuff?


I would say so. This is what I am using: http://medivet.ca/products/oxalic-acid-99-6/



hex0rz said:


> Like i said before i dropped the ball and didn't do the testing i should have in August. Hopefully i can be one to add to the experiment next year.


Have you treated or checked your mite levels since then?


----------



## Stephenpbird

An interesting short video on OAV. It shows the difference when one vaporizing wet OA, compacted OA and crystal OA. Not very scientific but it does show there is a marked difference in time taken and that one can even vaporize OA effectively with a candle.
https://www.youtube.com/watch?v=ano0l4St8kE


----------



## hex0rz

Your right, it is no indicator. What i meant was that it is producing a vapor of oxalic acid. 

The unit is functioning, and producing. But it's still unclear to how to harness it. 

I speculate that the way it vaporizes compared to the pan is different because of like stated before with it being pushed by hot air. 

I bet is making a much smaller crystal than the pan.


----------



## MT204

Stephenpbird said:


> An interesting short video on OAV. It shows the difference when one vaporizing wet OA, compacted OA and crystal OA. Not very scientific but it does show there is a marked difference in time taken and that one can even vaporize OA effectively with a candle.
> https://www.youtube.com/watch?v=ano0l4St8kE


I did a quick video this afternoon to show the difference in "my" vaporizer between 1/2 tbls OA out of new container, 1/2 tbls OA with water added and a 1/2 tbls OA pill. 1/2 tblsp is about 6 grams so way more than ever needed, just easier to measure time.
The plain OA took about 25 seconds, The very wet OA about 55 seconds with lots of vapor and the very compacted OA pill about 1 minute. All completely vaporized with almost no ash...in my vaporizer.
I realize its not a lega but does show there is a huge difference in vap time!
https://www.youtube.com/watch?v=FnFh1hNJsko


----------



## Arnie

Dang, Mark (MT204), that vaporizer works great! Nice work!

Hex, I think you may be on to something with the Lega. The air flow is diluting the OA vapor so much that not enough OA is getting into the hive. Like if I wanted to take a spoonful of cough syrup so I poured it into a gallon jug of water and drank a glass. I'm getting more fluid but less medicine. So even when I see the vapor coming out the top of the hive it is way too diluted to be effective.

I tested it again on Sunday, let the Lega blow vapor for about 90 seconds. Counted mite drop for two days, got maybe 30 mites.
On Tuesday I used my JB 200 wand and counted mites this morning. About 150. 

So the Lega is not getting enough OA into the hive. 
I use the same OA for both, so I don't think the OA quality is the issue here.

So, if your theory about too much air is correct, I wonder if I increased the temp and slowed down the fan would the OA vapor be concentrated enough?
I'm guessing No.

So,what if we could reduce the size of the exit hole. Would that slow down the air enough to keep the OA from getting too diluted?

Any of you folks more knowledgeable about mechanical stuff have any ideas on that?

I need to take a trip to the hardware store to see if I can rig up a reduced size tube attached to the Lega; maybe 1/4 inch.


----------



## jim lyon

Arnie said:


> Dang, Mark (MT204), that vaporizer works great! Nice work!
> 
> Hex, I think you may be on to something with the Lega. The air flow is diluting the OA vapor so much that not enough OA is getting into the hive. Like if I wanted to take a spoonful of cough syrup so I poured it into a gallon jug of water and drank a glass. I'm getting more fluid but less medicine. So even when I see the vapor coming out the top of the hive it is way too diluted to be effective.


This theory actually makes a lot of sense. It brings into question the whole principle of using hot air.


----------



## texanbelchers

I don't have one yet, so this may be obvious. On the Lega, is all of the air forced into the hive or is there another vent? In a modified design could the heated air be kept separate from the OA flow?

MT204, is your OA chamber closed? That is, is the vapor flow just from expansion?


----------



## mgolden

FWIW, review my version of OA vaporizer.

http://www.beesource.com/forums/showthread.php?331431-OAV-Vaporizer.

Most of the air of the heat gun bypasses the hive. he hot air flows over the brass end to boil the OA.

There is a 1/4 inch hole in the cap. Needed some hot air flowing through the 1/2 copper tube to prevent the vaporized OA from condensing and crystalizing on the edge of the tube.

Used it this past Sunday, and mite drop was 300(have done four previous OAV with Varrox, 7 days apart). At 470C, there is first water vapor and at about 90 secs the OAV starts. Could run heat gun hotter, but not sure what impact on OA. Ran it 8 mins and OA all vaporized.


----------



## zhiv9

The instructions that initially came with my Lega unit said to set to gun to 2 or 3 (it has 3 settings). The updated instructions on Lega's site has reduced temperatures and says to set it to 3. If you have the Steinel gun, you can reduce the air flow by lowering the setting to 1 or 2 but keep the temperature setting the same.

The theory that there is too much airflow only works if you assume that most of the OA is leaving the hive in the thinner vapour. Otherwise, regardless of the air flow, if the OA is being vaporized and blown into the hive it has to be going somewhere.


----------



## MT204

texanbelchers said:


> I don't have one yet, so this may be obvious. On the Lega, is all of the air forced into the hive or is there another vent? In a modified design could the heated air be kept separate from the OA flow?
> 
> MT204, is your OA chamber closed? That is, is the vapor flow just from expansion?


Yes.


----------



## Arnie

I think the dilution of the vapor makes it less deadly to the mites, no matter how much you blow into the hive. Just doesn't have enough oooomph to kill more of the mites. Just my opinion.

So Monday, I will try to rig up a fitting to reduce the exit tube diameter. Hoping that helps. 
Lower the fan speed, increase the temperature, , concentrate the vapor.


----------



## crofter

If the sublimated (vaporized) OA remains in a very high temperature air stream its temperature *will* continue to rise. How quickly will it decompose into the components (formic acid, carbon dioxide, carbon monoxide, water vapor)? If this is so, would the subsequent cooling of the decomposition components cause reversion to the desired air borne, fine OA sublimate particles? My take on it is that the product we are looking for exists at a temperature around ~320 F. 

Could the high temperature air stream be working against us?


----------



## Stephenpbird

I am not sure about this idea that the airflow is diluting the OA so much that it's losing it's effectiveness. Why? Simply because OA acid gives good results, over 90 % kill rate, over a wide dosage range of 1/2 a gram right up to 3 grams. Also If you look at how much OAV is produced using the candle, its hardly noticeable and takes up to 10 minutes to sublimate 1 gram, but still gives extremely good results.
I wonder how effective OAV is in a hive that has very high humidity ie one that is ripening nectar or syrup. Is anybody treating while or soon after feeding? Maybe while there is a flow on?


----------



## liljake83

ofcoarse i am feeding while treating winter is just around the corner


----------



## zhiv9

I am feeding as well. 

With the hives nearly broodless and after 3 treatments I am finally seeing results:

Yard 1
Starting mite level: avg 6.4% - max 8%/min 2%
After 1 treatment: avg 9.5% - max 12%/min 2%
After 2 treatments: avg 8.2% - max 12%/min 5%
After 3 treatments: avg 4.2% - max 6%/min 1.3%

A good reminder than OA is a good treatment for broodless or nearly broodless colonies. Unfortunately mites were too high for too long in this yard, so I'll likely end up combining 25-30% of them before wrapping for winter.


----------



## Ian

I've had beekeepers email me telling me with the VM, 1 broodless 10 sec treatment and waiting a few days to test had eliminated mites from their nest.


----------



## zhiv9

Ian said:


> I've had beekeepers email me telling me with the VM, 1 broodless 10 sec treatment and waiting a few days to test had eliminated mites from their nest.


That's what I was expecting from the unit when I bought it. Basically equivalent performance to OA dribble without having to split the boxes or break the propolis seal. I treated the yard for a 4th time last night after checking the results of the 3rd treatment. In my mind that should pretty much clean them up. In hindsight, I should have put formic or MAQS on them initially and just used OA to clean up later. I had expected faster results than this with OAV.


----------



## Stephenpbird

liljake83 said:


> ofcoarse i am feeding while treating winter is just around the corner


I sure quite a few are, the question is, Is it reducing the effectiveness of OAV?


----------



## swarm_trapper

I have tried both the Lega and the VM, and for mite kills there was no comparison the VM was close to 100% phoretic kill.

With the Lega I could not get a good kill, rolls three days later were either the same or up.


----------



## Allen Martens

Several observations after a couple of rounds of OAV this fall:

When a hive is broodless, mites levels come down quickly after treatments. After 2 round during the last week and a half the mite levels on my broodless hives is down to zero. The hives with brood in them the mite levels have not come down much at all.

Hives with higher levels of mites seem to brood later into fall. They don't seem to shut down. This is just an observation I've been noticing.

Nucs with queens from this summer are still have a fair amount of brood present. Varroa numbers are remaining stable in these nucs after 2 treatments but not going down.

I don't think any of the forced air vaporizers provide a consistent dose and quality. If you are not seeing a nice white spot at the point where the vaporizer is blowing into the hive (for the VM) you probably didn't good OA dose to the hive.

I wonder if temperature and hive activity has affects the results. I have been trying to treat when hives have a loose cluster but bees are not flying much. Is OAV successful at higher temperatures when bees are leaving the hive?

OAV seems to be very effective during broodless periods, which unfortunately is a moving target.


----------



## Ian

Allen, when a good fog is coming out of your device, how many seconds do you blast the hive? And does your hive treatment roughly calculate to 2g per hive?


----------



## Allen Martens

I've been going about 8 seconds per hive. Lots of billowing out of the hive after that period of time if the vaporizer is smoking good.

I don't really know about the dose. Very difficult to tell with the vm. Some days it works very well for me and some days it doesn't. Big difference between how much OA you are using and how much you are "dosing". If too hot it is decomposing not vaporizing or if overload is is melting and spurting out. If I get a nice white dusting at the point of entry I think I am getting a good dose.


----------



## Ian

Thx for that 
Extremely useful


----------



## aran

What's vm stand for?


----------



## Beekkirk

vm- vmvaporizer http://www.vmvaporizer.com/

Just did a dozen mite washes today after 2 treatments with the varrox 1 week apart. I have got my average mite load down to 0.9%. My average mite load after 3 treatments with the lega was 6%. My average mite load before treatment with the lega was 6%.

I think one more shot to make it a full 3 treatments with the varrox will get me down to 0%. My plan is to treat once more right before queens start laying next spring! 

Extremely disappointed with the lega but happy that I have now gotten my mite load under control. Unfortunately I only have about 100 out of 120 solid packed hives. I think I've got about 20 that were falling from mites.


----------



## aran

Holy cow how much does one of these vm
Vaporizers cost??


----------



## aran

Holy cow how much does one of these vm
Vaporizers cost?


----------



## Daniel Y

From What I found. $3600. The Holy Cow must be tax.


----------



## Beekkirk

They have apparently stopped selling that model. They have another upgraded model coming out soon that is going to be $4000-4500. But hey if it works, is durable and saves ya time its worth every penny.


----------



## snl

There's another unit coming into the market soon..
http://www.youtube.com/watch?v=yYl63Akou3E&sns=em


----------



## jim lyon

Beekkirk said:


> They have apparently stopped selling that model. They have another upgraded model coming out soon that is going to be $4000-4500. But hey if it works, is durable and saves ya time its worth every penny.


I agree. I called and left messages then emailed them. No response.


----------



## Beekkirk

snl said:


> There's another unit coming into the market soon..
> http://www.youtube.com/watch?v=yYl63Akou3E&sns=em


Do you know who is going to offer this for sale in the us? Its probably 220v tho.


----------



## snl

Yes, we'll have a 110 model.


----------



## Beekkirk

snl said:


> Yes, we'll have a 110 model.


When? Approximately how much $?


----------



## snl

Beekkirk said:


> When? Approximately how much $?


I'm told limited quantities within a month and approximately $385


----------



## Beekkirk

snl said:


> I'm told limited quantities within a month and approximately $385


Put me down for one please! Looks like about 20 seconds per hive, any feedback on durability?


----------



## snl

Beekkirk said:


> Looks like about 20 seconds per hive, any feedback on durability?


Unsure. I'm told the one you see in the video has been in use for a year. 
Lots of issues getting them here. Language and customs being two of them.


----------



## wildbranch2007

snl said:


> I'm told limited quantities within a month and approximately $385


so how do you control the temp. while using propane or what ever they use in Europe?


----------



## snl

wildbranch2007 said:


> so how do you control the temp. while using propane or what ever they use in Europe?


If you look at the video, you'll see it is controlled electronically


----------



## wildbranch2007

snl said:


> If you look at the video, you'll see it is controlled electronically


I have looked at the video multiple times, so I'm guessing the little box that you can't see the numbers but look like they keep jumping from not on to 200 is controlling the temp?


----------



## Ian

jim lyon said:


> I agree. I called and left messages then emailed them. No response.


I had a multi email conversation within hours of my inquiry


----------



## Ian

snl said:


> I'm told limited quantities within a month and approximately $385


Interested


----------



## jim lyon

Ian said:


> I had a multi email conversation within hours of my inquiry


How recently? My inquiries were mid Sept.


----------



## Ian

Mid last week
Very helpful 
He told me delivery within 2 weeks


----------



## Ian

I left things too long , I'm borrowing a neighbours, going to buy one on my off season


----------



## snl

wildbranch2007 said:


> I have looked at the video multiple times, so I'm guessing the little box that you can't see the numbers but look like they keep jumping from not on to 200 is controlling the temp?


That is correct.


----------



## jim lyon

Ian: Nice to hear. One would think they would respond to someone with US dollars for sure. . Very puzzling that multiple calls with voicemails followed by emails would get ignored. Too bad, Especially since I subsequently wasted $500+ on a Lega with heat gun.


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## Ian

Apparently the updated model has addressed some of the original annoying issues 

Cut the cheque ! Lol


----------



## swarm_trapper

Jim they responded to my emails in hours also, last week. They told me I could get one in two weeks but an updated model will be out the end of November.


----------



## jim lyon

At this point I think I may wait and see about their new model and also check out some others on the market. Did about 500 hives with the Lega and the mite drop seemed pretty spotty so we trickled the remainder of the outfit.


----------



## Ian

jim lyon said:


> At this point I think I may wait and see about their new model and also check out some others on the market. Did about 500 hives with the Lega and the mite drop seemed pretty spotty so we trickled the remainder of the outfit.


The guy who rented me his VM said the same thing. Said the efficacy of his vapour treatment was spotty at best and went back to trickle.
He was having trouble with douses


----------



## Beekkirk

Can mites become resistant to oa?


----------



## snl

Beekkirk said:


> Can mites become resistant to oa?


Been lots of discussion on this, search BS. But with over 20 years of use in Europe and no resistance, that says something. Jennifer Berry also says no.


----------



## hex0rz

*Well, i will be truthful, i was able to check on the hives over the weekend. Had a break in the weather to take a quick peek at them to see how they were faring. 

Lo and behold the hive that produced the most honey was so weakened that they were only 4 frames of bees at best. 

Pulled some frames and turns out the queen was replaced for some reason. Can't say for sure why she was gone. They did rear a new one and found her but i think she's a virgin and i know she won't get mated. 

I can't really say that i have any confidence in this one that i think I'll let them be and see how it turns out. If i can get in again in a week or two I'll see if the written is actually laying viable brood. I don't see how much more helpful the extra bees would be to another hive. 

But the big kicker is, i saw a couple bees with dwv!! So I'll join that bandwagon for a while that the lega did not perform as it should have. 

Although, upon peeking at the other hives they had good numbers. Although I'm not confident in what the mite load is at. Thinking i might do another mite treatment for peace of mind. 

So I'm investigating this further and looking at what i can do to possibly improve on the idea. 

So tonight i recorded some video of the unit with the lid off:

https://youtu.be/aH0RRktCyoI

The first time i vaporized the powder in the hopper, it was a measured two grams. There is a distinct difference between temperatures and also fan setting. 

One of the biggest takeaways from this is the understanding of why the lega preforms in the manner it does. You will notice that when it burns on the hottest setting it fully vaporizes the oa. But i dunno exactly whether it's burning it also or not. The camera seems to catch the vapor crystal as it blows into it. 

But on upon lowering down to the operating temp vaporizing slows down and something else occurs. It will boil then solidify back into crystal form. Then it really slows down. This crystal left over is then broken back up and it proceeds to vaporize again. This is where i think one of the fatal flaws is. 

The questions herein lie:

1. Can the unit be trusted that it can disperse the oxalic acid so effectively that small doses are just as effective? If not, then how can the speed of vaporizing be increased?

2. How can we ensure the unit actually vaporizes the powder in full instead of going "stale" on us?

My thoughts on the matter are, comparatively, how hot does a glow plug vaporizer get? Can someone shoot their pan with a temp gun to find out? If we can turn up the operating temp higher closer to 1200 degrees without comprising the oxalic acid then it would aid in speed and effectiveness. 

The other point is introducing something to the unit to ensure the oxalic acid vaporizes completely without hanging after a while. I was thinking of two ways to achieve this:

1. Introduce a small heat sink into the cup to evenly distribute the heat in the cup so the oxalic acid can't hang. 

2. Introduce some sort of agitation device like a stirrer or some other way to break it up. I was thinking about cutting some plate steel in the size and shape of the glass view and reseal it to the lid. Drill a small hole in the center and then insert a bent rod that matches the profile of the cup. Then just spin it ever so often. 

The other alternative as well is whether or not the way the heat is introduced into the body of the unit is causing problems. Could it be improved by drilling some holes into the cup to maybe get the air to swirl inside the cup before leaving the unit?

Well, i don't have anything else to say, except i wonder if anyone else have feedback on this subject or not, or if this just proves the whole idea behind the unit should be abandoned. I would hope there is still something that can be done to make it better.


----------



## grozzie2

hex0rz said:


> But on upon lowering down to the operating temp vaporizing slows down and something else occurs. It will boil then solidify back into crystal form. Then it really slows down. This crystal left over is then broken back up and it proceeds to vaporize again. This is where i think one of the fatal flaws is.
> ...
> 
> My thoughts on the matter are, comparatively, how hot does a glow plug vaporizer get? Can someone shoot their pan with a temp gun to find out? If we can turn up the operating temp higher closer to 1200 degrees without comprising the oxalic acid then it would aid in speed and effectiveness.


You need to read down on this page:- http://scientificbeekeeping.com/oxalic-acid-heat-vaporization-and-other-methods-part-2-of-2-parts/

The pertinent part is this


> How does oxalic vaporization work? In the CRC Handbook of Chemistry and Physics we find that upon heating oxalic acid, the water of hydration boils off first, then at 315°F the oxalic acid starts to sublime (go directly from solid to vapor), and finally at 372°F any oxalic acid which has not yet sublimed decomposes to formic acid and carbon monoxide.


What you describe in the first piece above, is exactly what you want to happen. OA comes to us as oxalic acid dihydrate when it's in crystal form, that's a form where the OA molecules are bound to a water molecule. The first phase of heating is to boil off the water, and leave pure OA crystals as the temp goes over 212f, which then sublimate to form the vapor we want in the hive after the temp heads above 315. But if you heat it to hot, then a chemical reaction starts, and the stuff starts breaking down and will no longer do any good. It needs to be heated above 315f, but, not above 372f, so if you blast it at 1200 like you are suggesting, then you may as well not do it at all, because that's far to hot for the OA to remain in crystal form and sublimate into the hive.


----------



## MT204

And there in lies the great debate with OA!
Take for example water. At sea level it boils and can not be heated higher than 212F.
So you can't "burn" water because it doesn't get any hotter in an open vessel, it turns to steam/vapor.
Some will argue that it's the same principle with OA, the only way it can get above that magic number and turn into Formic acid is in a laboratory in lab conditions?
So lets say that one could burn OA in a open vessel and it could turn into formic acid?
Well according to this http://scientificbeekeeping.com/oxalic-acid-questions-answers-and-more-questions-part-1-of-2-parts/ and other reading formic acid is also a mite killer?
So the mites could be getting the double treatment if one could turn OA into Formic acid?
If you check out this safety data sheet for OA http://dept.harpercollege.edu/chemistry/msds/Oxalic acid dihydrate JTBaker.pdf it states that at "149 - 160C (300 - 320F) Sublimes". doesn't say any thing about turning into anything else.
This info also shows a temperature range of 300-320f, is this difference due to altitude? Does it even make a difference like the boiling point of water at different altitudes?
So what is the definition of "sublime"? http://www.merriam-webster.com/dictionary/sublime. "to pass directly from the solid to the vapor state"
Here's some more info. How to make Formic acid from Oxalic acid https://erowid.org/archive/rhodium/chemistry/formic.acid.html. Note method #2 states "A good yield of formic acid *cannot* be obtained by merely heating oxalic acid"
I'm not a chemist, take all of what I have typed with a grain of salt. Just my 2 cents.


----------



## Arnie

MT204 said:


> "A good yield of formic acid *cannot* be obtained by merely heating oxalic acid"
> I'm not a chemist, take all of what I have typed with a grain of salt. Just my 2 cents.


Can you do us a favor and measure the temp inside the OA cup of the vaporizer you made? Yours works like the ones in the European videos; drop in the OA and in 25-30 seconds the acid is vaporized. 

I heated my Lega until the metal acid holding cup was 385 degrees and dropped in 2 grams of OA. It bubbled for about 4 minutes, never really vaporizing until I jacked up the temp on the heat gun.

I'm thinking the 372 degree limit for OA is not valid. I'm guessing much higher temps in the acid pan are not just acceptable, but desired.


----------



## MT204

Arnie said:


> Can you do us a favor and measure the temp inside the OA cup of the vaporizer you made? Yours works like the ones in the European videos; drop in the OA and in 25-30 seconds the acid is vaporized.
> 
> I heated my Lega until the metal acid holding cup was 385 degrees and dropped in 2 grams of OA. It bubbled for about 4 minutes, never really vaporizing until I jacked up the temp on the heat gun.
> 
> I'm thinking the 372 degree limit for OA is not valid. I'm guessing much higher temps in the acid pan are not just acceptable, but desired.


Give me a day or two and I'll fire it up and get a temp reading.


----------



## Arnie

MT204 said:


> Give me a day or two and I'll fire it up and get a temp reading.


Thanks


----------



## crofter

Radiant heat can almost instantly raise the temperature of finely divided particles. Passing through a high temperature air flow can also virtually instantly heat a substance that is in an expanded state (low mass per unit of area)

"Take for example water. At sea level it boils and can not be heated higher than 212F.
So you can't "burn" water because it doesn't get any hotter in an open vessel, it turns to steam/vapor." 

This often parroted statement suggest that the ensuing gas also cannot be increased in temperature! Absolutely flawed conclusion!

The hot air stream devices may be much more susceptible to heating the sublimed gas or vapor into the decomposition range. Yes formic acid has miticidal properties but what percentage of the decomposition is carbon dioxide, carbon monoxide, water vapor etc. Keep in mind that an effective dose of Formic is much higher than the dose of OA.

Something seems to be causing some aberrations in expected outcomes with some OA devices. This application (heat sublimation) of oxalic acid is not a common one in industrial applications so the actual sequence of events and control protocol is not well known. Latching onto some misconception that _seems_ to be common sense can really hold back finding out what factually explains the events.


----------



## MT204

"Take for example water. At sea level it boils and can not be heated higher than 212F.
So you can't "burn" water because it doesn't get any hotter in an open vessel, it turns to steam/vapor." 

"This often parroted statement suggest that the ensuing gas also cannot be increased in temperature! Absolutely flawed conclusion!"

Note that I stated "in an open container" and was referring to water.
Yes, steam for example can be heated and even super heated but in a closed vessel.
Now in this day and age never say never but I couldn't find any info how to heat a vapor (water) in an open atmosphere?
Yes I would agree that the particles(?) in the vapor "might" be harmed by the higher temp of the heat guns, if that's even possible?
Its at times like this you wish you had a friend that was a chemist living next door!


----------



## crofter

MT204 said:


> "Take for example water. At sea level it boils and can not be heated higher than 212F.
> So you can't "burn" water because it doesn't get any hotter in an open vessel, it turns to steam/vapor."
> 
> "This often parroted statement suggest that the ensuing gas also cannot be increased in temperature! Absolutely flawed conclusion!"
> 
> Note that I stated "in an open container" and was referring to water.
> Yes, steam for example can be heated and even super heated but in a closed vessel.
> Now in this day and age never say never but I couldn't find any info how to heat a vapor (water) in an open atmosphere?
> Yes I would agree that the particles(?) in the vapor "might" be harmed by the higher temp of the heat guns, if that's even possible?
> Its at times like this you wish you had a friend that was a chemist living next door!


Yes i notice your disclaimer; I quite agree with superheating of steam and have worked on many installations. The implication taken by many people is that the ensuing vapor cannot be further heated.. simply not true. Also the supposed requirement that it can only happen in an enclosed vessel: think of the science fair project of igniting a flamable object at room temperature by a radiant source on the other side of a pane of glass. Being enclosed simply makes the applied heat more effective due to reflection.

We dont know how quickly the decomposition can occur or what percentage reduces the effectiveness of the OA sublimate fog. It is in a rather fleeting and delicate state and it effectivness supposedly is dependent upon being redeposited in extremely fine particles on all hive contents. I have not heard that once decomposed, that the components, formic acid, carbon dioxide, carbon monoxide, water vapor, will recombine into OA. it may be a one way transition.

The heated air stream of the heat gun models with temperatures kicked around of 550 to 1000 deg. F. would seem to have the _potential_ to elevate the temperature of the OA sublimate. 

I am not a chemist and I am not sure a chemist would have the experience of dealing with the mechanics of heat on gasses. I do have a fair bit of time as a process operator and steam fitter. Some processes have some tricky quirks and the solutions often dont lend themselves to being solve by so called common sense or simplistic analogies. They can be blinders to finer resolution!

There is some reference in previous discussion that point to a time component for the sublimation to take place, and that decomposition temperatures are easier to reach by part of the charge if heat input is more rapid.


----------



## MT204

One of the experiments (outside the bee hive) that I did was with OA that was all but dissolved in water.
Some felt the length of time for vaporization had to do with the moisture content of OA which it does, in my opinion.
I had also made some OA pellets just so I didn't have to measure out at the hive. They took longer to vaporize also.
With water added I got a lot more vapor and it took longer to vaporize completely, which stands to reason because there was more water. 
The water in theory boils off first at aprox 212 F (sea level) and the OA would have been right after or even during the vaporization?
What if the steam from the water actually helped to disperse the OA vapor or even OA crystals and maybe even kept the OA vapor cooler (not burnt) and in suspension longer?
Would be interesting to figure out how to measure the temperature of the vapor? 
Any ideas?


----------



## crofter

It would be interesting to see some controlled experiments with OA vaporization ( not sure if that is technically correct term) This does not seem to be a common process in the use of oxalic acid.

I too have seen differences in Oxalic acid when freshly opened and after picking up moisture. I commonly dont cool my tray completely between cycles to save warm up time and battery. I have dumped the OA in a fully hot tray and though it quickly "gets rid" of the charge, the water of hydration boil off and the sublimation fume off seem to happen on top of each other. Again no way of assaying the smoke (or steam or whatever) and did no comparisons of effectiveness. For the most part my mite counts are so low it is mostly a ritual anyway! 

It is not easy to instantly measure the temperature of something that is essentially a gas. 

I do have the feeling that a fast cycle is perhaps NOT the best goal though. I think there are some good heads getting together to see if there are real, controllable aspects to this issue and we will get some concensus on the issue.


----------



## hex0rz

Well i guess for the lay man, one way of knowing is to just do it to a hive and find out!

I'm not sure if I'm a candidate for that right now considering everyday its been raining recently. 

I suppose i should be the one to actually just put it into practice and see what happens considering i brought the idea up. Not to say no one else can, but if you don't consider it a waste of your time,then go ahead! It'd be nice to have someone else apart of this little experiment. Doesn't have to be many hives, just at least one hive that receives it in this manner while the rest are done with commonly accepted way. 

I guess then we would need rolls/washes or board counts before and after...

I did my observation hive over the weekend with my heat gun and took a moment last night to watch them. Turn i realized the bottom was rittled with mites.

I'll have to possibly video that sometime just for fun.


----------



## Arnie

Three times I have vaporized with the Lega and counted the mite drop for 3 days. 
Then, on the 4th day, I have used my Varrocleaner and counted the mite drop.

All three times the Varrocleaner has killed many more mites. I estimate the Lega is killing about 30% of the phoretic mites while the wand is killing the rest.

Ultimately, I want to kill mites. I care not one bit if it is because the hot air is degrading the OA vapor or if it is diluting the OA or a combination of the 2 or something else.
I want results and so far have not gotten those results.

The last thing I will try when I have a chance is to reduce the vapor exit tube to about 1/4 inch to see if that concentrates the vapor into a more deadly gas.

After that I am done with the Lega.


----------



## Arnie

I have the afternoon off so I can play around a little.

I took my Helisyer JB200 unit and put a thermometer probe wire between the aluminum heat pan and the sheet metal wing that it's attached to. Fired it up. This unit usually takes a minute thirty to about a minute forty to evaporate 2 grams OA. At a minute thirty five the temp was 565 degrees F. It was above the 372 mark for about 45 seconds. So, once the water boils off, this thing is vaporizing at a higher than recommended temp. 

So now I know when I am using a wand I am vaporizing at too high a temp, according to the 'experts'.
Let me tell ya, that JB200 kills mites. 

Now I am less worried about too high a temperature.


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## crofter

Perhaps some of the blown devices are simply powering the conversion of too large a charge of OA powder per unit of time/area compared to the weight OA in the time / area experienced in devices like the varroa cleaner. My device though homemade after many experiments arrives at something very like the heilyser in area, power and time needed to complete a cycle. I think the varroacleaner pretty much falls into the same relationships. Maybe that is the sweet spot in having the give off the most effective product.

Cycle time is the big attraction with the blown in models and that certainly is desirable to be commercially viable. Maybe something like a much larger, more gently heated evaporating surface would be the answer. I havent played with these units at all so this is entirely armchair quarterbacking but I have played with somewhat parallel problems where the solution was increasing heat transfer surface area, slowing the flow and dropping the temperature gradient. That flys in the face of compactness and cost of unit though.

We still dont know if there is definitely a shortfall with some of these designs or what the actual issue is on chemical terms.


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## Daniel Y

crofter said:


> "Take for example water. At sea level it boils and can not be heated higher than 212F.
> So you can't "burn" water because it doesn't get any hotter in an open vessel, it turns to steam/vapor."
> 
> This often parroted statement suggest that the ensuing gas also cannot be increased in temperature! Absolutely flawed conclusion!
> 
> QUOTE]
> 
> Provide references for this claim. show how steam is superheated without being under pressure.
> 
> from one source:
> Steam is traditionally created by heating a boiler via burning coal and other fuels, but it is also possible to create steam with solar energy.[1][2][3] Water vapor that includes water droplets is described as wet steam. As wet steam is heated further, the droplets evaporate, and at a high enough temperature (which depends on the pressure) all of the water evaporates and the system is in vapor–liquid equilibrium.[4]
> Superheated steam is steam at a temperature higher than its boiling point for the pressure, which only occurs where all liquid water has evaporated or has been removed from the system
> 
> Note only dry steam can be heated above 212 degrees at sea level. The question remains how to produce dry steam. You conveniently ignore this step in your claim. I say the same is true about decomposing OA. there is a lot that is conveniently being ignored about how you would go about that. The claim is that if OA decomposes at 370 degrees then it simply takes heating it to 370 degrees. Which is no more true about OA than it is simply heating steam above 212 degrees can be done.
> 
> This is what one source describes about superheated steam.
> 
> Superheated steam is a steam at a temperature higher than its vaporization (boiling) point at the absolute pressure where the temperature is measured.
> The steam can therefore cool (lose internal energy) by some amount, resulting in a lowering of its temperature without changing state (i.e., condensing) from a gas, to a mixture of saturated vapor and liquid. If saturated steam (a mixture of both gas and saturated vapor) is heated at constant pressure, its temperature will also remain constant as the vapor quality (think dryness, or percent saturated vapor) increases towards 100%, and becomes dry (i.e., no saturated liquid) saturated steam. Continued heat input will then "super" heat the dry saturated steam. This will occur if saturated steam contacts a surface with a higher temperature.
> Superheated steam and liquid water cannot coexist under thermodynamic equilibrium, as any additional heat simply evaporates more water and the steam will become saturated steam. However this restriction may be violated temporarily in dynamic (non-equilibrium) situations. To produce superheated steam in a power plant or for processes (such as drying paper) the saturated steam drawn from a boiler is passed through a separate heating device (a superheater) which transfers additional heat to the steam by contact or by radiation.
> 
> Note it requires a secondary and separate heating device. in other words to get oa vapor above 312 degrees it would require your entire hive was above 312 degrees. maybe another convenient fact being ignored. Note steam cannot get above 212 degrees if in the presence of water. air contains water. Likewise OA vapor cannot get above it's vaporization temperature if in the presence of unvaporized OA. The heat goes into vaporizing the remaining OA until it is all vapor.


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## Allen Martens

Water in oxalic acid dihydrate is water of crystallization/hydration. The water molecules are released at a temperature very close to the boiling temperature of water for oxalic acid. Other hydrates release water molecules at temperatures much different than the boiling temperature of water.

Even though the water is said to be boiled off from the oxalic acid dihydrate, in reality the process has nothing to do with a phase change; the bonds between the water and oa are broken and water molecules are released.

Daniel 

Steam/fog/water vapor - all a bit nebulous terms aren't they?


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## Daniel Y

Allen Martens said:


> Steam/fog/water vapor - all a bit nebulous terms aren't they?


No, What I find nebulous is references to decomposition without any effort to explain what it is. I say that is intentional. References to superheating again without any attention to how that is accomplished. again making claims but intentionally concealing details of how that could be accomplished. that is being cloudy and foggy. intentionally. I call it deceitful.


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## texanbelchers

I took the quoted text as a pun. I don't believe anyone on here is being deceitful. We are all trying to understand what is happening. Specifically, why different users experience wildly different results and what can be reproduced to work well.

Unless you are using an open pan, like the Varrox style, the sublimated OA is confined. Specifically in the Lega design it is confined until it leaves the exit pipe and is dispersed in the hive. The air flow is hot enough to cause the sublimation in the first place and the same air is heating the rest of the unit. I would think superheating could occur as it contacts these heated areas of the container and indeed within the heated air flow itself. I don't have one to test, but you could check the temperature of the cover and exit pipe to see the extent of the possibility.

I have been thinking about a design where the heated air is exhausted outside the hive and the OA path is sealed for expansion and exit into the hive.


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## hex0rz

I'm no professional in the matter, and in fact that's why I've brought the issue up. But i would have to say that in my train of thought, despite the idea of the acid being in a confined space, i don't think it plays a big role in the matter. 

While the cavity inside is under a pressurized state i don't think it would make that big of a difference compared to an actually sealed vessel undergoing pressurization.

The input of the heat vs the output is what needs to be looked at after the unit is up to a good temperature. This is all in my theorizing though, lol.


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## Stephenpbird

Strange how the world works , these questions or very similar are discussed in a German forum. So I'll provide some thoughts from there, which need further scrutiny.



hex0rz said:


> But on upon lowering down to the operating temp vaporizing slows down and something else occurs. It will boil then solidify back into crystal form. Then it really slows down. This crystal left over is then broken back up and it proceeds to vaporize again. This is where i think one of the fatal flaws is.


The thought here is the OA goes into a liquid form then back into crystals but if the temp is not high enough these crystals form with a large amount of airspace between them. This insulates/prevents the crystals from sublimating because the right temp can't be reached. Hence if you break them back up they begin to vapourize again.



hex0rz said:


> The questions herein lie:
> 
> 1. Can the unit be trusted that it can disperse the oxalic acid so effectively that small doses are just as effective? If not, then how can the speed of vaporizing be increased?


The smaller the dose the better a wand works, why is it different for a Lega? Maybe it's the shear size of the unit. What's is the mass of a lega and how does that compare to a wand and how much extra heat is required to get it up to working temp? 



hex0rz said:


> 2. How can we ensure the unit actually vaporizes the powder in full instead of going "stale" on us?
> 
> The other point is introducing something to the unit to ensure the oxalic acid vaporizes completely without hanging after a while.


This answer needs further experimentation! A drop of Glycerin added to a gram or two of OA, just enough to make the OA look damp. By doing this the OA, when heated, turns liquid and stays liquid until it sublimates. Because the re-crystallization never happens the "stale" stage is bypased. 

I would be interested in reading about everyone's experiences when Glycerin is used as an additive to OAV.


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## MT204

Stephenpbird said:


> This answer needs further experimentation! A drop of Glycerin added to a gram or two of OA, just enough to make the OA look damp. By doing this the OA, when heated, turns liquid and stays liquid until it sublimates. Because the re-crystallization never happens the "stale" stage is bypased.
> 
> I would be interested in reading about everyone's experiences when Glycerin is used as an additive to OAV.


According to this, and I'm no chemist but it appears that adding Glycerin is used to help create Formic acid?
https://erowid.org/archive/rhodium/chemistry/formic.acid.html


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## Stephenpbird

MT204 said:


> According to this, and I'm no chemist but it appears that adding Glycerin is used to help create Formic acid?
> https://erowid.org/archive/rhodium/chemistry/formic.acid.html



Have a look at the ratios needed to produce formic, how much do you think will be produced with just a drop of glycerin? Plus they state in method two that the oxalic still sublimates. 
Glycerin is hygroscopic, its addition is to try and improve sublimation by absorbing the moisture present in OA.
Try it and see if it works.


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## MT204

Stephenpbird said:


> Have a look at the ratios needed to produce formic, how much do you think will be produced with just a drop of glycerin? Plus they state in method two that the oxalic still sublimates.
> Glycerin is hygroscopic, its addition is to try and improve sublimation by absorbing the moisture present in OA.
> Try it and see if it works.


I've added water and it takes longer to vaporize a batch. I have a bottle of Glycerin I'll add a bit and vaporize it and see if it makes any difference.


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## 109651

Can anyone shed light on the Lega unit as I believe mine may be defective but have nothing to comapre it to? Does your heat gun (Steinl HL2010 E) fit tightly to the Red vaporization unit, or even screw into the threads on the unit? Even with the screw on the side of the unit mine doesn't seem to fit at all and I have to hold both pieces together. Did yours come with directions? I can't figure out what the slot and bolt are for on the entrance blocking unit. Frustrated. Thinking about returning it...


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## zhiv9

WaggleDance said:


> Can anyone shed light on the Lega unit as I believe mine may be defective but have nothing to comapre it to? Does your heat gun (Steinl HL2010 E) fit tightly to the Red vaporization unit, or even screw into the threads on the unit? Even with the screw on the side of the unit mine doesn't seem to fit at all and I have to hold both pieces together. Thinking about returning it...


This is normal - not right - but normal. I have an earlier version without the set screw. I think initially they probably fit pretty well together with friction, but the water meter base manufacturer must have changed the tool that makes the threaded end. Lega seemed pretty surprised when I brought it to their attention that it was not longer a tight fit. I shimmed mine with some aluminum foil to tighten it up and its pretty good. Just fold a small rectangle to the thickness required, push it against the threads and then slide the gun in.

Pretty much all of the vapourizers are slightly scaled up homemade units. None of them are what you would called a "polished" product. The vmvaporizer is probably the closest and it is still a work in progress with a revision coming out soon.


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## 109651

zhiv9, thank you, I will give that a try if the new unit doesn't fit correctly. I've decided to stick with the Lega. My unit is unfortunately defective, but I just received a call from Blueskybeesupply after sending them pics of a defect, and they are making it right. Best customer service ever!


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## hex0rz

Well tried some oa with glycerin. Did 2 grams glycerin with 2 grams oa. Very wet. It did vaporize and took some time to do too. It seemed to calm things down at higher Temps but i couldn't say what the end product really became. 

If i tried to vaporize a hive like that,i risk introducing something to them that i don't know what it is. This may be something to entertain more when spring comes around again where i might be willing to sacrifice a hive just to see. Which goes against all my acts of self preservation. 

Although i did hit my hives again with just oa at 1000f with a half full cup. Vaporized until i had it coming out of every Crack and crevice. Definitely smoked allot and longer than before. If this weekend is decent, I'll take a look at the bottom and see if it dropped any mites. With 10 hives i had to refill the cup at 8 hives. Definitely got allot of oa in each hive if it performed as i hoped.


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## Arnie

Hex, you kept the temp at 1000F the whole time? Nice.
What fan speed?


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## hex0rz

Arnie said:


> Hex, you kept the temp at 1000F the whole time? Nice.
> What fan speed?


I cranked it to 1200 to get it going then down to 1000. Didn't have it go stale on me and just kept boiling out mostly until it was all used up. 

Fan speed, high.


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## hex0rz

adamant said:


> i just received in the lega-vaporizer-unit from bluesky and a Steinel Heat Gun Kit, 25th Anniversary Edition from amazon.
> 
> bluesky did not send direction and i plan on doing my hives Wednesday.
> can someone post a step by step direction on the procedure?
> 
> thank you.. ant


Blue sky doesn't supply directions because they're not the manufacturer. Lega should be the one to provide directions. 

I have a video posted up this thread on how i approach it, and I think it's within the first 4 pages of this thread.

But our recent discussion is showing that the unit is not performing as we anticipated. Understanding why is the ongoing issue. 

If you feel inclined, try warming the unit up at 1200f then turn it down to 1000f after you start seeing vapor. Give us an account of your experience.


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## hex0rz

Well fwiw, getting home i checked my observation hive. I also vaporized it with my other hives on Sunday. So its been about a 48 hour period. I noticed a much more significant drop this time compared to before when running the heat gun at a lower temp. 

The proof in the pudding will be if i can peek at the bottom boards of the hives outside and see what kind of drop they got. 

So, it does show promise! If only i could get more of you guys to try it out..


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## zhiv9

hex0rz said:


> If you feel inclined, try warming the unit up at 1200f then turn it down to 1000f after you start seeing vapor.


You don't want to leave it at 1000+ deg F for very long or you will start to melt the red plastic housing.


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## hex0rz

zhiv9 said:


> You don't want to leave it at 1000+ deg F for very long or you will start to melt the red plastic housing.


Nope. I've stripped it to the bare essentials...


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## hex0rz

Today was a warm day! Warm enough they got to fly. So before i headed to work i was able to get some video of them in action. Didn't have enough time to obviously crack open the hives to get a better view, but the amount of bees coming and going is promising. 

Towards the end you'll notice the last hive is quiet. That one had the queen issue. I'm hoping tomorrow will be warm enough where of got enough time to give them a better look over and also check the bottom board. 

The only thing I've been doing to these hives is using the lega to vaporize on a 3x weekly interval. Did it when i got them. After the flow and now before winter. I would have already suffered from mite collapse if the unit never worked. 

I'm not saying it's 100% effective, but it sure beats other alternatives!

https://youtu.be/_HrSYhKlFJE


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## hex0rz

Here's a video of vaporizing today at the new Temps:

https://youtu.be/_WNJ4bv500c


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## Daniel Y

watching that video, I had a couple of thoughts. One is that if you notice you don't see anything coming out of the nozzle for 2 or three inches. my suspicion is that is because all there is is hot air and vapor. this tells me that OA vapor is in in fact invisible just like many vapors are. It then turns to the white cloud. this is the vapor having cooled and re crystalizing. Second is that it looks to me like the hot air is creating a chimney effect in the hive. this would cause an updraft carrying out the OA and drawing in fresh air from below. just like a chimney is meant to do. And that effect will not stop just because you stop the vaporizer. it will continue until the hive cools again. Drawing in fresh air and removing your OA crystals.


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## hex0rz

I can agree with what your saying...

Any other given time, the lids would be closed and their wouldn't be a top entrance. So the chimney effect would not exist in that situation. 

The one thing i did take point on after recording that video is cutting or making a board that attaches on the output tube. That would help seal the entrance off and give the hive a better positive pressure environment. Then it would probably saturate the hives better. 

In any case, if a person were that concerned, they could always seal the hive with something like a rag after vaporizing to stop any chimney effect that may occur. 

As you can tell from the population in the hive, my methodology seems to have been working well as this is all I've done since the beginning of this season.


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## Arnie

hex0rz said:


> Here's a video of vaporizing today at the new Temps:
> 
> https://youtu.be/_WNJ4bv500c


Nice! I'm going to try that. When I get a chance to treat them with your new method and then follow up with the wand, I'll see how the mite numbers add up. 
Good job sticking with it.


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## Arnie

OK. Just tried the new temp. 
What a difference! I covered the entrance with a towel and after 30 seconds or so the fumes were pouring out from the top cover (I have the covers tipped up slightly for ventilation) and even two, three minutes after I had moved on to another hive, when I pulled the towel, vapors were still coming out the entrance. Some bees came out of the hives white, looked like they had rolled around in powdered sugar. 

One of my backyard hives has a sticky board so I will check it tomorrow. 

Fingers crossed, this may be the ticket. Thanks, hex.


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## hex0rz

Arnie said:


> OK. Just tried the new temp.
> What a difference! I covered the entrance with a towel and after 30 seconds or so the fumes were pouring out from the top cover (I have the covers tipped up slightly for ventilation) and even two, three minutes after I had moved on to another hive, when I pulled the towel, vapors were still coming out the entrance. Some bees came out of the hives white, looked like they had rolled around in powdered sugar.
> 
> One of my backyard hives has a sticky board so I will check it tomorrow.
> 
> Fingers crossed, this may be the ticket. Thanks, hex.


Very good! I'd like to see what the 24 and 48 hour drops yield you!


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## Arnie

hex0rz said:


> Very good! I'd like to see what the 24 and 48 hour drops yield you!


My plan is to count the mites for the next two, three days; then use the wand to see if there are significant live mites remaining that the Lega missed.

I'll keep everyone posted.


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## hex0rz

Messing around with the hives, i noticed that im seeing a significant mite drop. Mites littered all over the bottom,at the entrance and on the wax paper where the they are eating the protein feed!

I'm thinking i might do a total of 5 treatments instead of 3. Dunno what my mite load is and feel like i need to make up for past treatments. 

As of now,my best guess is that I've been helping them walk that fine line threshold. 

Hoping this doesn't equate to dead hives come spring...


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## Arnie

Keep treating them until you get the mite load down for the winter.

Now that you have figured out how to get the effective vapor into the hives keep at it. 

As long as the weather is above freezing you can hit them with a treatment. 

If I still see mites in large numbers I treat them until the sticky board is pretty clean after a treatment. I do 4 treatments a week apart after supers come off, but if after that 4th round the mites are still numerous I hit them again.


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## Arnie

OK. Here are the numbers:

24 hours...68 mites
48 hours...112 mites
72 hours...62 mites
After 72 hours treated with wand vaporizer.
24 hours post wand treatment...72 mites
48 hours...45 mites

Those numbers are a HUGE improvement over past Lega vaporizations. I had gotten very poor mite drops before using the new temp. And when I followed up with the wand there would be 5 times the mites for the next few days. So this new temperature and better volume of vapor is the way to go for me.

I added a second set screw to hold the Lega and heat gun together better. Much better.

Also, one last thing. I re-read the first couple pages of this thread and something Bernhard said jumped out at me. To paraphrase: The temperature in the heat gun is different than the temperature inside the Lega which is different from the temperature of the escaping vapor. 

The message I took from that is to work backwards from the point of good 'smoke' to find the best temperature for your individual set-up. That is what hex did with the 1000 degree temp. 
And since we (hex and I) both use a Wagner heat gun, maybe the heat gun brands produce different levels of heat?

Make of this what you will.
There is a definite learning curve when using the Lega, but it can be effective once dialed in.


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## jim lyon

I knew someone would crack the code. Good job Arnie! 
I think, though, the trick on a unit like this is getting uniformity in treatment. Mine put out lots of vapor but the mite drop was inconsistent. In hindsight I wasn't checking mite loads before and after, could be some hives just simply had more mites in them. Our mite loads never did get too high this year so, perhaps, I was just assuming there was going to be a huge drop based on past experience .


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## hex0rz

Before, I had not used anything to cover the entrance while vaporizing. Today I used the original board sent with the lega unit. I cut it down to fit the entrance and went at it. WOW! What a difference it made! I could not believe the cloud that came rolling out of the hives. I highly recommend anyone still doing their treatments with the heat gun method to make something to block the entrance up during vaporizing.

I wish I could have gotten video of it, but it was dark and by myself anyways. Just a quick tip today...


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## jim lyon

My unit came with a foam lined entrance block with a round hole drilled in it sized to accept the exit pipe on the Lega. It seemed to do a pretty darned good job of sealing up the entrance, even if they varied in size, and forcing all the vapor through the hive.


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## Daniel Y

Arnie said:


> OK. Here are the numbers:
> 
> 24 hours...68 mites
> 48 hours...112 mites
> 72 hours...62 mites
> After 72 hours treated with wand vaporizer.
> 24 hours post wand treatment...72 mites
> 48 hours...45 mites
> 
> Those numbers are a HUGE improvement over past Lega vaporizations. I had gotten very poor mite drops before using the new temp. And when I followed up with the wand there would be 5 times the mites for the next few days. So this new temperature and better volume of vapor is the way to go for me.
> 
> I added a second set screw to hold the Lega and heat gun together better. Much better.
> 
> Also, one last thing. I re-read the first couple pages of this thread and something Bernhard said jumped out at me. To paraphrase: The temperature in the heat gun is different than the temperature inside the Lega which is different from the temperature of the escaping vapor.
> 
> The message I took from that is to work backwards from the point of good 'smoke' to find the best temperature for your individual set-up. That is what hex did with the 1000 degree temp.
> And since we (hex and I) both use a Wagner heat gun, maybe the heat gun brands produce different levels of heat?
> 
> Make of this what you will.
> There is a definite learning curve when using the Lega, but it can be effective once dialed in.



Nice to know. I have been saying 1200 degrees for the element or heat source with never testing a thing.


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## CTO322

Thanks Bernard, how do you preheat the gun. Do you turn it on to 220° with no OA in the crucible (my word-container of OA)? Or do you take the crucible out while it is on at 220°?
Charlie



?


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