# Homemade oxalic acid vaporizer



## Glen H

Hi,
I made one, that was very inexpensive. I purchased a 12 volt car/travel coffee cup heater that plugs into a cigarette lighter in a car. I also used a 3/4 inch copper pipe end cap.
I formed the heaters coil around the copper cap. it works good. I also made a measuring scoop out of a 1/2 inch copper end cap and soldered a handle to the end of the cap.

Still need to make up a simple handle for the Vaporizer.

You can buy the heater on Ebay.









Glen


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## Steves1967

Thank you


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## Glen H

Here is the scoop, made with a 1/2 inch copper pipe end cap. this is the correct size measure. 






Glen


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## ky_mike

Here is mine. I machined the tray out of aluminum, stuck a diesel glo-plug in the side and added the metal rod with a chisel handle. Takes about 1 minute to evaporate. I actually made a few more in which I machined the tray to where the glo-plug sticks in the middle and it has a small tray on each side to hold the oxalic, but I don't have a picture of it.....yet


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## westernbeekeeper

Woow, they all look great. Glen, how do you use yours? Or is that just a measuring spoon? Is there someplace that sells the vaporizers? Where do you get your OA?


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## Glen H

westernbeekeeper said:


> Woow, they all look great. Glen, how do you use yours? Or is that just a measuring spoon? Is there someplace that sells the vaporizers? Where do you get your OA?


The electric heater one is connected to a car battery that I take to the hives and set on the ground
I have an adaptor cable with alligator clips on one end that goes to the battery and the other end of the cable has an outlet on it that the heater plugs into. The other picture with the wooden handle is the OA measuring scoop that is the correct size measure for the vaporizer.

You can buy Vaporizers online I believe they are over $100.00.

The OA in the States can be purchased on line or in a hardware store it goes by the name of wood bleach. Just make sure if you buy wood bleach, that OA is the only ingredient. 

I got mine on Ebay.

Glen


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## westernbeekeeper

Oh I see, I didn't realize both post were yours. Yeah, I thought I'd seen the commercial vaporizers for pretty pricey. I am thinking about dribbling OA this fall. What are the mite knockdown stats for OA?


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## WBVC

What is the correct size measure....how much oxalic acid does one use per hive when vaporizing? Have you tested that system to see if the oxalis acid vaporizes?


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## Glen H

The measure is one cap full of crystal roughly. (1/2 inch copper plumbing end cap) . I have used it four times it takes about a minute or two to heat up and vaporize the OA. 1 gram per every deep on the hive EG: two deeps 2 grams two deeps one medium 2.5.....
I do a test run outside the hive and use a stop watch to monitor how long it takes for the crystals to turn to a liquid, then unplug the heater and see how long it takes for it to totally vaporize.


Glen


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## JStinson

Glen H said:


> I do a test run outside the hive and use a stop watch to monitor how long it takes for the crystals to turn to a liquid, then unplug the heater and see how long it takes for it to totally vaporize.
> 
> 
> Glen


Is this standard procedure? I'm thinking seriously about switching to OA and need to know exactly how it's done.


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## Glen H

JStinson said:


> Is this standard procedure? I'm thinking seriously about switching to OA and need to know exactly how it's done.


You can watch the "Fat Beeman" in action doing a treatment. He has two videos of doing treatments here is one, you can find the other on his channel.

http://www.youtube.com/watch?v=sQp9pdAOjdo

Glen


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## cristianNiculae

So 1 cup (1/2) equals 1g. Right?
The dose is 1g/hive body.
http://www.dave-cushman.net/bee/oxalicthorne.html


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## MichaelShantz

Optimal sublimation is 315F and above 375F or so it melts and instead of getting oxalic acid vapor you will get formic acid and carbon monoxide. So I used the heating element from an old iron and a bimetal thermostat to set the temperature. It slides in under the screened bottom board.
http://picasaweb.google.com/MichaelJShantz/BeeHive4302010#5681736830921254930
I like GlenH's idea for use with car battery power. Might be better with temperature control.
Here is a simple one made from a soldering iron with no thermostat but at 23W it takes way too long to sublimate.
http://picasaweb.google.com/MichaelJShantz/BeeHive4302010#5685396769979254738


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## WWW

JStinson, 
The 1/2" copper cap will give you approximately 1 gram of Oxalic and as stated above use 1 gram per deep, this measure does not need to be extremely precise. It is best to give the vaporizer a trial run outside the hive to see how long it will take to sublimate into vapor, then make sure the vaporizer is cooled down before refilling. Place the vaporizer into the the entrance of the hive about half way if possible and connect to the battery per your pre-assessed time, I have found that it is helpful to seal off the entrance with some cloth while vaporizing but some do forgo sealing the hive and have reported good results. Do one treatment per week for 3 weeks. Here is a thread which gives good locations to find vaporizers. http://www.beesource.com/forums/showthread.php?288080-Where-to-buy-oxalic-acid-vaporizer


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## stajerc61

Remember to wear your protective safety breathing device because that stuff will kill you.


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## Steves1967

Wow! Thank you all so much for the info! Now I just need to find out which glo-plug is cheap at my local auto parts store. I already have some half face respirators and OV acid gas cartridges. I plan on being pretty religious using them.


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## WWW

The plug used by Heilyser is a Bosch 80010, these plugs have M12x1.75 threads on them which need to be machined off to fit the Heilyser but perhaps you can design your vaporizer to use this thread. This Bosch plug generates the correct amount of heat that is needed for sublimating Oxalic. 

Remember to treat the hives in the fall after the supers are pulled just to be on the safe side, it has been said that Oxalic can be applied with the supers on but I just do not want to take that chance.


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## Rader Sidetrack

> I am thinking about dribbling OA this fall. 

You may be interested in _Jim Lyon'_s approach to applying OA without vaporizing it. Read the posts by _Jim Lyon_ starting at post #133 on this page: http://www.beesource.com/forums/show...644#post989644

Jim expands on his comments in following posts. You will have to ignore the heckling from the peanut gallery about OA (oxalic acid). Jim has thousands of hives, and years of experience, and seems to be a straightforward guy.


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## crofter

Here is what I made. Uses two VW glo plugs. Threads ground off and held in with set screws. About 2 1/2 inches wide and 3/4 inch high. Solid aluminum so fair bit of mass and takes a little over a minute to start vapor. The bees return to normal activity in a very short while and I noticed no dead bees aside from a few who fell into the cup. Treated once in november last fall and again early in April and mite count is near zero at present but I am very isolated. 

My impression is that it does not kill open brood but just is not as effective when 75% of mites are on capped brood since it does not penetrate cappings. Will work if you do 4 rounds 6 days apart.


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## WWW

Crofter, that thing looks like it would last a lifetime lol. Nice bit of craftsmanship.


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## WBVC

Interesting as on one of the videos showing vaporization they first checked it was melted...then put it back in to treat. Perhaps many are using a substance quite different from they thought. I think it may have been a Fat Bee Man video.


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## Steves1967

Crofter, do you know the part number on your glo-plugs?


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## crofter

I dont remember off hand but it is somewhere here in a post; It is for VW but not sure whether before or after the TDI. engine. Radar? Some glowplugs must be used with a controller or they go like flash bulbs so you must get one that is for full 12v. Actually the ones I used were stamped rated 11.5V . I would not go to the trouble of threading for the plug. That and a tapered seat is to withstand 1500 or so PSI in an operating diesel. Set screw is simpler. Use a 20 ft or so cord and you have no need to be anywhere near the fuming hive unless you are trying to do rapid fire and jerk the vaporizer out to put in the next hive. I leave in and hive blocked for 15 min and there is no fumes. OA unless heated, gives off no more fumes than sugar would. If you over heat or apply heat too quickly it will flash to CO and formic acid. As you heat it it should first liquify then boil off over a minute or so and the Oxalic vapor looks like thick white smoke. It is deposited over the interior in minute crystals. Stay out of that cloud just as you would stay out of the smoke of burning plastic.

I had fun making it but the price of a proven design is around a hundred bucks. Having one thin enough to slip through a standard entrance is a big plus as you can do it without disturbing the hive and in any weather.


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## Rader Sidetrack

_Crofter_, if you were asking about a part number for a glo-plug in one of _your _posts, I didn't see one. But in this thread, which you did also post in:
http://www.beesource.com/forums/showthread.php?273419-My-Oxalic-Acid-Vaporizer&highlight=plug

There is a reference in post #44 to an Autolite #1104 glow plug. These seem to retail for around $10.


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## WWW

Yes the Autolite 1104 has the same rating as a Bosch 80010, the autolite plug is a little bit longer and slightly cheaper than the Bosch. I agree that it is better to remove the threads as this helps to keep the unit shorter in height, the Heilyser is only 1/2" in thickness.


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## crofter

Thanks on finding those numbers. If you are making something up don't go too small with the bowl. When it starts to melt the OA bubbles and froths quite a bit. The first unit I made tended to boil over. Plan to do a few runs in open air to get timing right. I give about a minute and pause 30 seconds then a couple of 15 second shots. There is a bit of delay, then overshoot effect. 

I had notions of trying a CPU cooling fan and a housing around the unit with a nozzle to blow vapors into any shape of entrance. The nozzle would have to be something like paper though or the vapors condense on it like hoar frost and never make it inside. That can be a problem with the crack pipe designs (besides being too close to the action)


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## ky_mike

Here is the type I make now. Big difference is it has 2 trays to hold the oxalic. I figured the heat would dissipate better this way. I use the Autolite #1104's in mine and have it rigged to plug into the 12V outlet on my ATV. Makes it pretty easy.


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## WWW

ky mike, that is an interesting design, I like it, great workmanship and there is no need to remove the threads.


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## WWW

crofter, I agree with the larger bowl idea, the only complaint that I had with the heilyser was that the bowl was a little small which allowed the bubbling OA to spill out a little so I machined a larger pan with thicker walls and it was a big improvement, no more spillage.


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## crofter

KY Mike;

One glow plug only? I notice a bit of scorch marks on bottom boards. Plan to give a wrap of glass cloth and an aluminum foil skin to keep the heat where it is needed. It works though and may be one of those things that dont happen.


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## burns375

Glen H said:


> Hi,
> I made one, that was very inexpensive. I purchased a 12 volt car/travel coffee cup heater that plugs into a cigarette lighter in a car. I also used a 3/4 inch copper pipe end cap.
> I formed the heaters coil around the copper cap. it works good. I also made a measuring scoop out of a 1/2 inch copper end cap and soldered a handle to the end of the cap.


FYI Glen H be careful with hand bent coils. I use work at GE appliances as an engineer, Mg0 is a the heat conducting dieletric filler between the sheath and Nickle-Chrome wire. If the sheath is bent to sharply the MgO is displaced and the heating wire can short to the sheath in a catastrpophic failure. In the industry we call it zippering, the sheath basically zippers open, sparks, mini-eplosion, etc. 

IMO glow plug is much safer route.The heater way very well function just fine for you, just a bit of caution.


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## Glen H

Thanks for the FYI Burns, much appreciated and good point. I used to work with Metal sheathed heat tracing cables and remember the white compound that kept the element centered and away from the out coating. Trying to remember the name?? Pyro something??
I have actually started making a two glow plug heater. Got it working, just need some finishing touches, then I'll post some pictures of it.


Glen


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## burns375

Glen H said:


> Thanks for the FYI Burns, much appreciated and good point. I used to work with Metal sheathed heat tracing cables and remember the white compound that kept the element centered and away from the out coating. Trying to remember the name?? Pyro something??


Yes, exactly the powder keeps the Heated wire (Nickel Chrome) centered within the sheath. The white insulating powder is Magnesium Oxide (MgO), under many different trade names. In the manufacturing process the rods are packed straight and bent into desired shape with cnc benders. There is a minimum bend radius and amount of bends that is considered safe, I don't remember those specs.

Good Luck!


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## Glen H

Finished the new vaporizer today and have tested it out a couple of times.
But I have not tested it in a hive yet.
I didn't have any 1/2 plate aluminum so I used two sheets of 1/4 inch and one sheet of 1/8
Drilled the pocket with a hole saw in the one of the 1/4 inch plates and the 1/8 plate.
Sandwiched the plates together and then milled it to shape. The handle rod is aluminum stock.
I added a switch too.
After adding the heat shield on the bottom, I ended up milling the 1/8th off the top to make it slimmer. 













Glen


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## Steves1967

I made four like KY Mike's design, thank you! Ran all four in parallel and got a bunch of hives done right quick!

One apiary is in a sheltered location with very still air. The vapor stayed like campfire smoke and chilly scouts. I am very glad I chose to use my APR first thing.


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## ky_mike

Steves1967 said:


> I made four like KY Mike's design, thank you! Ran all four in parallel and got a bunch of hives done right quick!
> 
> One apiary is in a sheltered location with very still air. The vapor stayed like campfire smoke and chilly scouts. I am very glad I chose to use my APR first thing.


Awesome! Glad you liked my design!


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## Steves1967

So after treating all my hives for my first round I am curious what kind of residue people are finding in their vaporizers. It seems that there is almost always a little crud left over. Thoughts?


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## Glen H

Got around to using my new homemade 2 glow plug vaporizer. It appeared to work well off of a 12 volt ridding lawn tractor battery. I like the on off switch! Took about three minutes to vaporize and finish off making vapour. Put in through the back of the hive under the SBB.
I like putting it in the back of the hive compared to the front entrance.

Glen


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## Glen H

Steves1967 said:


> So after treating all my hives for my first round I am curious what kind of residue people are finding in their vaporizers. It seems that there is almost always a little crud left over. Thoughts?


Mine has a caked on light grayish residue after using it. I just scraped it out after using it.


Glen


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## Steves1967

So today I did my second weekly treatment, all haves had many dead mites on the bottom boards. A couple hives that overwintered last winter had thousands. Literally thousands of dead mites from last weeks treatment.


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## Glen H

Steves1967 said:


> So today I did my second weekly treatment, all haves had many dead mites on the bottom boards. A couple hives that overwintered last winter had thousands. Literally thousands of dead mites from last weeks treatment.


How long did it take, after the treatment to see the big mite drop? Did it happen the next day or was it bit by bit over several days the mite drop showed up? Was the big drop after the first treatment or after the second one?
How far apart were the treatments. I'm still learning to use my Vaporizer. 

Glen


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## Steves1967

Glen, I have been super busy so I had not been out to see them at all in a week. The last time was when I treated them.


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## cristianNiculae

It would be so nice if somebody with enough experience on using different kind of vaporizers would write an article on the subject and post it as "info" on the main site. For now the information is pretty dispersed throughout the forum. We cannot buy vaporizers in all countries and if we were to buy them in Europe for example we would pay a lot of money including expensive transport.

Regards,
Cristian


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## julysun

Here is a video link, there are several on the web that demo the simple to complex vaporizers.

http://www.youtube.com/watch?v=ALHz4B1vqKo


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## Bob J

Glen H said:


> How long did it take, after the treatment to see the big mite drop? Did it happen the next day or was it bit by bit over several days the mite drop showed up? Was the big drop after the first treatment or after the second one?
> How far apart were the treatments. I'm still learning to use my Vaporizer.
> 
> Glen


Glen, On my hives the main mite drop was after two days..... Checked the first day and was disappointed but the second day had a huge drop.... Each successive day for the next 3 or so had less and less drop....


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## Daniel Y

The simplest vaporizer I have used is a small metal dish. make it very small and shallow. Over a hooka coal. I now have the $99 think from Canada and with the cost of other treatments it has paid for itself a couple of times over. I am waiting to see how long it lasts. I made my own but it cost as much as the one from Canada before I was finished.

Best news is I never see signs of mites in my hives anymore.


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## Robbin

Glen H said:


> How long did it take, after the treatment to see the big mite drop? Did it happen the next day or was it bit by bit over several days the mite drop showed up? Was the big drop after the first treatment or after the second one?
> How far apart were the treatments. I'm still learning to use my Vaporizer.
> 
> Glen


Hi Glen, In my experience big mite drops follow the first two treatments, most on day 2 and 3. I treat 7 days apart. Drop counts begin to fall after the 2nd treatment. How much and how quickly depends on how much brood there is. I like to treat at least 3 times a week apart to cover a brood cycle. That way all the mites in the brood have emerged and can be treated.
following the 3rd treatment counts really fall off, thou I usually treat 4 times in a row. this year I've decided to go with 3 sets of 3 treatments. Now, before the supers go on, as I am in florida and building fast, then again after the supers come off and we're in the middle of the derth and once more in late fall as the brood cycles down. In Florida we have mild winters but tons of mites. 
I didn't lose a hive over winter. Lost a small nuc last summer to SHB which you guys don't even have.
Good luck,
Robbin


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## TELMAG

I am new to bees and came across Glen H's Homemade oxalic acid vaporizer and made one myself but had some issues and not as neat as Glen's model. when I put it together and tested it the heater elements melted the plastic housing, guess I had the heater elements too far back in the plastic body. Have to look for some small insulating material to overcome it and also give support to the 3/4 pipe cap end and the immersion heater element. 
Wondering if anyone else made one similar to Glens model and if they had similar problems.


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## MichaelShantz

snip


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## Glen H

I only powered that small heater for seconds at a time.
Try not heating it for as long. Just give it shots of power on and off.


Glen


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## BeeAttitudes

Never mind......sorry.


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## snapper1d

Here is one I put together this morning and posted it on another link.Its was blowing glow plugs though so When I get that resolved I think it should work good.


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## nater37

The amps on the battery make all the difference on time. My pickup battery takes 2.30 mins and my motorcycle takes 4.30 mins to finish off 2 grams. I put a 20 foot 12 gauge wire so I don't have to tote a battery around.


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## snapper1d

Is the tip of your glow plug some how against the plate.With the blown glow plugs I was told they had to be against the metal to keep from over heating and blowing.Mine blew in only a few seconds.


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## nater37

Yes the block is machined to fit the glow plug. I was nervous about blowing the glow plug after putting in water after treatment, but has worked fine so far.


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## snapper1d

So your heating element is toughing the metal.Well thats what I was needing to know.I will have to wrap mine with copper and put it in and then mast it down to touching the element real good.I can do that with my vice and not get it squeezed down without putting a lot of pressure on it.


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## brushwoodnursery

I'm fairly new to OV treatment but I had a pretty cool idea and wanted to run it by some folks. I had a friend who scorched her frames and melted some wax leaving it in too long. How can you tell? I also have trouble with this and timing and spilling and all the sundry things associated with using a flat burner on a long stick that I can't see doing its thing inside the hive. For me, the timing gets difficult to monitor when the element is hot. The squirrels in my brain started running around and I thought: why not something that is more portable, easy to use and you can see when the vapor is done? 
My idea is to use a battery operated tool as a platform and hook in a small fan, a heating element and a clear plastic or glass "cone" to blow the vapors into the hive. I'll attach a sketch. 
Before i go shredding and building, i wonder if any of you have thoughts about amperage, voltage, correct vaporizing temperatures and the concept in general.


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## snapper1d

I think there are already some vaporizers out there that do that.I think the problem is the vapor goes everywhere inside and out.I saw a guy using one on youtube.But if you can come up with something that would work go go ahead and show us.There is always a better way doing everything.


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## Rader Sidetrack

>> use a battery operated tool as a platform and ...

Keep in mind that a typical commercial vaporizer (and many of the homemade ones using glow plugs) are approximately 150 watts. At 12 volts that is about 13 amps. At 18 volts that is 8.4 amps. Your tool battery will need to be capable of delivering that load for the length your heater "on" time. That may be a challenge for a typical tool battery.


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## brushwoodnursery

Rader Sidetrack said:


> >> use a battery operated tool as a platform and ...
> 
> Keep in mind that a typical commercial vaporizer (and many of the homemade ones using glow plugs) are approximately 150 watts. At 12 volts that is about 13 amps. At 18 volts that is 8.4 amps. Your tool battery will need to be capable of delivering that load for the length your heater "on" time. That may be a challenge for a typical tool battery.


Rader, thanks. This is the kind of data I need. I own a dewalt 20v drill with a 5ah battery so, if the process takes 5 minutes, I might be able to do a half dozen hives per battery/charge.

More data: I'm also looking at something called a PTC heating element that shuts itself off at a specific temperature by resistance. If I could mount a cup to that...


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## B.B.

Glen, constructed as per your directions and immediately burn the heater out. Used a AC heater which apparently was required to be submerged. How did you get around the submerge requirement. Your example was a DC heater but I would not expect that to make the diff.?? Please advise. Thanks B.B.


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## dadux

I got a little excited when I saw the 12 volt car/travel coffee cup heater with 3/4" copper pipe cap. But after I got the parts I realized it's too big for my hives. My entrances are 3/8". Same for the bee space below the frames. The heater coils are 3/4" tall and the copper cap is 15/16" tall.


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## desotohemi55

An easy to make pan/heat transfer unit for the glow plug, can be made out of a 3/4 inch copper pipe cap and 3/8 copper tubing. The tubing is flattened starting at one end until you have enough to start wrapping it around the pipe cap. keep flattening 
and wrapping until it goes 3/4 of the way around. Do not get ahead of yourself and flatten to much. Using a socket the same size as the cap to form against helps. You should end up with a press fit for the cap with round tubing sticking out. cut the remainder off with just enough off left to insert the glow plug you need to tap the copper ever so slightly to get a tighter fit for the plug. after this has been used a while the copper gets soft then you can tighten it more with pliers. The 3/4 inch cap can be cut down to height with a tubing cutter. Cost new, 2 dollars or less and works very well, and seems to match the times in the posts as far as vaporizing. The only problem may be height, mine finished out at about 5/8 inch which works for me on most of mine, but i just tilt the others back to slide it in. it helps to keep the frame bottoms scraped too.


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## johnmckeag

This following video is the best example of a DIY OA vaporizer. I wish the maker had provided details about the construction and a schematic. https://www.youtube.com/watch?v=q7SSPU4dlBo


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## crofter

I notice that the molten oxalic acid is overflowing slightly: The volume of the tray is marginal. Some of the proposed models are even smaller in tray volume. Some people who are treating for more hive space than a double deep would do well to consider enlarging the tray. Making it deeper rather than a larger footprint creates the problem of difficulty inserting in a standard entrance and more prone to scorching frame bottoms and wax dripping into pan.


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## BeeAttitudes

I did in this post:

http://www.beesource.com/forums/showthread.php?309065-Oxalic-Acid-Vaporizer-with-Temp-Controller&highlight=oxalic+acid+vaporizer



johnmckeag said:


> This following video is the best example of a DIY OA vaporizer. I wish the maker had provided details about the construction and a schematic. https://www.youtube.com/watch?v=q7SSPU4dlBo


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## Daniel Y

crofter said:


> I notice that the molten oxalic acid is overflowing slightly: The volume of the tray is marginal. Some of the proposed models are even smaller in tray volume. Some people who are treating for more hive space than a double deep would do well to consider enlarging the tray. Making it deeper rather than a larger footprint creates the problem of difficulty inserting in a standard entrance and more prone to scorching frame bottoms and wax dripping into pan.


It looks to me like there is far more OA in that tray than you would ever use in a hive. most likely for video purposes. Second that is an example of the OA crystallizing on any surface it contacts yet it was reheated and did eventually vaporize. I suspect that is due largely to the wind blowing it around. which would not be the case in a hive. Still the OA was vaporized. This issue is a matter of method not one of results. The OA can vaporize off the bees wings if that is what gets it vaporized. seems this design not only vaporizes the OA it also addresses the additional issues of cool surfaces where it is not wanted to remain. Seems a bit overkill in some regards.


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## johnmckeag

desotohemi55 said:


> An easy to make pan/heat transfer unit for the glow plug, can be made out of a 3/4 inch copper pipe cap and 3/8 copper tubing. The tubing is flattened starting at one end until you have enough to start wrapping it around the pipe cap. keep flattening
> and wrapping until it goes 3/4 of the way around. Do not get ahead of yourself and flatten to much. Using a socket the same size as the cap to form against helps. You should end up with a press fit for the cap with round tubing sticking out. cut the remainder off with just enough off left to insert the glow plug you need to tap the copper ever so slightly to get a tighter fit for the plug. after this has been used a while the copper gets soft then you can tighten it more with pliers. The 3/4 inch cap can be cut down to height with a tubing cutter. Cost new, 2 dollars or less and works very well, and seems to match the times in the posts as far as vaporizing. The only problem may be height, mine finished out at about 5/8 inch which works for me on most of mine, but i just tilt the others back to slide it in. it helps to keep the frame bottoms scraped too.


This is a pretty good idea. Can you offer any ideas as to creating a handle? By wrapping the 3/8" tubing around the cap, the holder for the glow plug is created. A hole could be drilled into the cap and a bolt or screw inserted. The threads would run parallel to the 3/8" glow plug holder beside it. A nut threaded down against the outside of the cap would keep it tight and secure. The threads could be screwed/threaded into the end of a shaft to create an long handle.


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## desotohemi55

hold on you are getting to complicated i will send pics and descriptions
asap


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## johnmckeag

BeeAttitudes said:


> I did in this post:
> 
> http://www.beesource.com/forums/showthread.php?309065-Oxalic-Acid-Vaporizer-with-Temp-Controller&highlight=oxalic+acid+vaporizer


Can you please tell me more about the bi-metal thermostat that you have incorporated into the circuit? I think it is a good idea. I called around to different electronics suppliers and learned that these aren't very accurate, sometimes varying 20F - so a desired 350F open may then open at 370F to break the circuit or it could be 20 degrees lower, 330F. I see that there are 12 VDC digital temp controllers on ebay for roughly $12, could this be another approach, in your opinion? 
On another note, I see that JB Weld is capable of withstanding 500F. If you drilled a hole on the side of a 2" copper pipe cap and slid in a 1/4" copper tube to lay along the flat bottom of the cap and then cover it with JB Weld to act as a heat sink, essentially embeding the copper tube holding the 60G glow plug hot end under the JB Weld. The whole point is my trying to make a vaporizer without the need for machining. Your thoughts please?


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## BeeAttitudes

The bi-metal disks do have some temp variation. The one I used worked out just right so I have no complaints.

Based on what I've seen, I don't believe OA sublimates (at least not at atmospheric pressure). It goes from powder to liquid then boils off. The temp won't rise above the boiling temp of liquid OA till all the OA liquid has boiled off. So I don't see the need for a temperature controller. A few reasons to use a temperature sensitive device to cut-off power to the heating element are:

1) To prevent the temp climbing excessively after the OA has boiled off. This could possibly prevent melting wax from the frames.

2) You don't have to time each treatment precisely to prevent overheating. It's much easier to treat multiple hives concurrently if you don't have to time each treatment and monitor closely to ensure the heating element doesn't overheat.

3) If you wire a light to the output side of the device that is supplying power to the heating element, you can visually see when the treatment is finished. Without a light to let you know the treatment is over, then you are back to using a timer to know when the treatment is over.

As for JB Weld, I don't know the heat transfer properties of cured JB Weld so can't speculate if it would be a good medium for transferring heat. For all I know, it may be a heat insulator (no idea).

It wasn't easy, but I made my device on a drill press. Drilled holes throughout the cavity as close as possible then used an end mill bit using an up/down motion as if drilling to remove essentially all the material. Finally, I clamped angle iron to the drill base, lowered the end mill bit to the bottom of the cavity (had a stop set so I wouldn't go too low), and slid the aluminum block along the sides of the angle iron to clean up the sides of the trough. I hope that makes sense.





johnmckeag said:


> Can you please tell me more about the bi-metal thermostat that you have incorporated into the circuit? I think it is a good idea. I called around to different electronics suppliers and learned that these aren't very accurate, sometimes varying 20F - so a desired 350F open may then open at 370F to break the circuit or it could be 20 degrees lower, 330F. I see that there are 12 VDC digital temp controllers on ebay for roughly $12, could this be another approach, in your opinion?
> On another note, I see that JB Weld is capable of withstanding 500F. If you drilled a hole on the side of a 2" copper pipe cap and slid in a 1/4" copper tube to lay along the flat bottom of the cap and then cover it with JB Weld to act as a heat sink, essentially embeding the copper tube holding the 60G glow plug hot end under the JB Weld. The whole point is my trying to make a vaporizer without the need for machining. Your thoughts please?


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## tnfiddler

What gauge wire do you use with the glow plug?


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## Daniel Y

tnfiddler said:


> What gauge wire do you use with the glow plug?


I used 14 gauge solid on time. it got so hot it left burn marks on the side of my hive. 12 gauge stranded does not have the same problem. you can also get 12 gauge or larger wire for hot applications. The sort of wire used in ovens etc. I would suggest 10 gauge or larger.
14 gauge for up to 15 amps
12 gauge for up to 20 amps
10 gauge for up to 30 amps.
I (amps) = V (volts) divided by R (resistance) you know volts are 12 if you use a 12 volt battery. R can be measures with an ohm meter. I Think you will find the amps are huge on these things. amps produce heat.


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## tnfiddler

Thank you Daniel


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## BeeBop

Well, I've only had bees for a couple of weeks so far but I figure I better get myself prepared for battle with mites sooner or later. So I built myself a OA vaporizer.

The glow plug is a Bosch F002 650 003. I have *no* idea what it fits or why it was in my junk box but it appeared just like magic when I was looking for other useful hardware for the vaporizer. It's rather longer than I would have liked, but I figured I'd already witnessed a miracle finding this one in my junk pile so I didn't complain.

The handle is from a busted bbq tool and all the aluminum bits were just laying around looking for something to do.
I put the glow plug in the center with a OA tray cut on each side of it. It holds 3 grams easily enough and it starts to bubble and smoke at about 90 seconds and takes about 4 minutes to fully cook off a 3 gram load.

It's fully functional now but I will add some timer electronics to shut it off after a fixed amount of time and probably will add a low battery indicator also.


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## tnfiddler

Does the heater end of the plug need to make contact with the aluminum block


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## BeeBop

Yes, the heater should be in good thermal contact with the block. Mine has 2 set screws in the bottom that clamp the heater in place.


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## tnfiddler

Mine threads in, so there is good contact there, but the element is not touching. I guess that's why its not getting hot


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## BeeBop

Yeah, the element needs to be in good contact not just the threaded part.
I drilled the hole for the element only very slightly larger than the element itself and put some thermal transfer grease down in the hole before I shoved the element in and clamped it in with two 8-32 set screws.

Here's the bottom view with the set screws. Ignore the one in the upper corner. Unimplemented feature...


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## gnor

Randy Oliver at scientificbeekeeping.com has some good info. Here's how to do an OA dribble: http://is.gd/U7JoLR


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## oldfordguy

Here's the OFG bottom board vaporizer I've been working on, I think it is going to work out well for my small operation. Although I use top-entrance only hives, it should be adaptable to about any screened bottom board.
http://mannell.net/?p=89


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## snl

oldfordguy said:


> Although I use top-entrance only hives, it should be adaptable to about any screened bottom board.


There is no reason you can't vaporize from the top down should you wish..........


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## oldfordguy

Certainly; I've vaporized from the top effectively in the past, but it wasn't nearly as easy as my new system.


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## johnmckeag

oldfordguy said:


> Here's the OFG bottom board vaporizer I've been working on, I think it is going to work out well for my small operation. Although I use top-entrance only hives, it should be adaptable to about any screened bottom board.
> http://mannell.net/?p=89


Passing the OA vapors through the SBB will cause the OA vapors to cool and deposit onto the screen. The vapors need waft up into the frames where the bees are located and contact the mites. The further the distance and the more obstacles (SBB) reduces the effectiveness.


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## oldfordguy

I thought about that; but only a very small percentage condenses on the screen. My main concern is the effect of the acid on the screen over time; it may well deteriorate the screen. If so, I will probably do away with the screen entirely and just use a removable slide in bottom. I haven't found the screen bottom necessary for ventilation, nor very beneficial to mite or small hive beetle in my area. I leave the slide-in board in all year round.


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## tnfiddler

I have a question for those of you who use a homemade acid vaporizer. Do many bees die from coming in contact with the vaporizer? Also, have you ever had a queen come in contact with it? Are you just taking the risk that the queen is not close by when you slide it in? Any danger of catching the hive on fire with all the heat?


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## Glen H

You may get a very small handful of curious bees get killed. I have not lost a queen let or many bees for that matter. If you run screed bottom boards you can put the vaporizer below the screen if you enter it from the back of the hive. I have mine rigged to enter the back of the hive with the slid out Board slid in. And the vapourizer under the screen. For my solid bottom bottom board hives I go in from the front. No real problem at all.


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## crofter

I smoke hard into the bottom entrance, quickly rake out the ladder comb under center two or three frames and push in the vaporizer. The queen bee would likely be the first one to run up the frames if she were in the bottom. You will kill a few bees but not as many as you would squish when stacking off and on to do an inspection


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## Mimzy

I use SBB, I know I can't use the white plastic cardboard to seal off the vapors, because it will most likely burn. My slot is very narrow - I have a piece of 1/4 plywood, but I can't get it in the slot. I looked at the hardware store and they have sheets of silver stuff in the stove pipe aisle. I'm guessing it's made of the same stuff as stove pipe??? It's very thin and would fit. My question is do you think I could use it to close off the bottom while I vaporize? Or will that sheet heat up and over heat my hive. Sorry this is not clear as to what this sheet of metal at Menard's is made of.


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## snl

Mimzy,
If it is stovepipe material, you're fine. Aluminum flashing works well also. You do not have to have a perfect fit, but you want to close off the openings of size.


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## crofter

Make a pair of tapered shims by cutting a piece of 3/4 x 3/4 wood 20" long, diagonally from end to end. Lift and separate the front of your hive from its bottom board and slip one of the resulting wedges under each side. Your front entrance is now about 5/8" higher opening. The first vaporizor I made a bit on the tall side needed this trick to fit in.

Similar pieces can also be used to instantly create additional entrances anywhere between boxes or under a top cover. I have a bunch of them precut. They will also create an instant hive bottom on any flat surface.


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## snl

Remember, if your BB opening is to small for the vap, you can always vap from the top down! Just make a two inch or so shim the size of the hive body, cut a slot in it for the vap, place the vap with OA on the top bars (you may want to place a small piece of wood or sheeting under it) cover with the top cover and vaporize. You can use the plastic or ??? to cover the screen bottom board if you have one. Quick and simple .....


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## gnor

You can also use a hive tool to raise the box off the SBB while you slide the vaporizer into the hive. It will then rest on the screen, and won't burn the plastic.
A long term approach might be to build up your SBBs so you can slide the vaporizer into the bottom entrance.


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## greasydog26

I recently made a vaporizer out of bar stock aluminum and aluminum rod... I used 12 gauge braided wire but it is getting really hot and I don't want to mess anything up... What kind of wire are you all using and should it be getting hot?


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## my2cents

This is very inexpensive to make your own, and the time to vaporize 2 grams is 2 minutes. Make your own.
http://www.ebay.com/itm/Mini-Portab...tric-Heater-/131562535428?hash=item1ea1bcfa04


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## BeeBop

Dang, how big is the pan on yours that it holds 2 OZ of OA ?


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## my2cents

BeeBop said:


> Dang, how big is the pan on yours that it holds 2 OZ of OA ?


Dang auto correct, LOL - no, wasn't paying attention.


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## Mimzy

I know you're supposed to take honey supers off before the treatment. I have two hives that are new this year, so I left them on so the bees could have the honey later on. I do want to know what does the OA do to the honey. Does it poison it for human consumption, or does it make it taste weird or what. Someone is going to ask me this question and I want to know the correct answer.


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## Chemguy

Mimzy said:


> I know you're supposed to take honey supers off before the treatment. I have two hives that are new this year, so I left them on so the bees could have the honey later on. I do want to know what does the OA do to the honey. Does it poison it for human consumption, or does it make it taste weird or what. Someone is going to ask me this question and I want to know the correct answer.


I know that folk say that oxalic acid is found naturally, but the truth is that you can get pretty sick from eating some plants that contain it (rhubarb leaves, for example). I don't know the levels that are found in natural (yet hazardous) sources, nor do I know the levels that would be left on honey supers after treatment. 

The OSHA PEL (permissible exposure limit) for oxalic acid is 1 mg/cubic meter, compared to 5 mg/cubic meter for cyanide. Although general exposure isn't the same as ingestion, I'd hazard a guess that it is the possibility of poisoning that leads to the recommendation to remove the honey supers.


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## Mimzy

Chemguy,
I can leave it for the bees to consume correct?


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## Chemguy

I believe so. After all, they get coated with the stuff and groom it off.


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## snl

*d) Oxalic acid was developed to the final-use stage as a drug in bees by the European Working Group for Integrated Varroa Control (CA 3686). In all EU countries, government approval is only given to a new veterinary medicament for use in treating animal diseases after the EMA, the European Union’s Agency for Evaluating Medical Products, has determined the maximum residue limit (MRL) of the active ingredient allowed in the final food product according to European legislation. This procedure is meant to protect consumers from toxicologically critical residues in foods resulting from medicines used on animals. For oxalic acid no MRL was available. The MRL establishing procedure was started in cooperation with A. Imdorf (Agroscope Liebefeld-Posieux, Swiss Bee Research Centre), J.M Poul (Agence Française de Sécurité Sanitaire des Aliments) and A. Wibbertmann (Fraunhofer Institute for Toxicology and Experimental Medicine), carried out as a joint project of many European countries and successfully finished in December 2003: oxalic acid was listed in Annex II of Council Regulation (EEC) 2377/90 (Rademacher and Imdorf , 2004). This means that the substance is evaluated as not dangerous, and no residue limit is needed to protect the consumer. On this basis every European country can apply for approval and the Concept of Integrated Varroa Control, as recommended by the scientific institutes for bee research, can legally be implemented. It was the first time that scientific institutes and beekeeper organisations worked together on a European level to establish the legal basis for drug approval in bees.*


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## Chemguy

Thanks, snl. I'm glad to know that the evaluation has been done.

Toxicology and industrial safety are complex areas, and once in a while numbers considered in isolation don't tell the whole story. The PEL that I mentioned above is one example. That PEL measurement assumes a constant exposure for 8 hours at the level specified, and in some cases is based on limited information. Many PEL levels were listed in the 1970's based on information available for similar possible substances, but without specific experiments having been conducted. It's good to know that a closer look was taken for oxalic acid in 2003, and that the information was updated based on real information.

Thanks again for updating us all on this. In my mind, this new (to me) information means that OA used according to label is not a hazard to human health.


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## Czarembo

Hello Glenn, 

Thanks for the information on the coffee cup heater and the cap for Varroa treatment. I'm wondering how long these elements last from your observations. Since the element is meant to immersed I'm wondering if you've had them fail on you after a certain period of time. Thank you.


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## JohnSchwartz

WWW said:


> Remember to treat the hives in the fall after the supers are pulled just to be on the safe side, it has been said that Oxalic can be applied with the supers on but I just do not want to take that chance.


Hi Bill ― a few years down the road now from this post. Are you still using oxalic in this method and what kind of results are you seeing? Thanks.


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## scooter58

I built mine and 12 others the same as KY Mike. I use an Auto lite 1107 glow plug as found on eBay for about $9.00 You don't need to thread the glow plug into the aluminum. I turned the threads off (you could file them off) and used a setscrew to hold it in. I drilled the hole for the glow plug to fit as tight to the glow plug as possible(slip fit) to aid in the heat transfer. I found you may want to cover the lead to the glow plug (+) with shrink tube or electrical tape so it doesn't short out on a hive cover. We had a glow plug die when that happened.
I bought my Oxalic Acid on eBay and got enough to cover my local dealer and myself for a long time to come..LOL

Yes I'm a newbie here but I've have bees since I was 8, I have white hair now but not from bees.
Scooter


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## A1B1

Like the looks of it. I read modern glow plugs heat up to 1000 degrees, would a 350 thermostat in series with glow plug affect it greatly.


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## gnor

I'm using a vaporizer similar to what glen made, and attached a coat hanger handle to get it to the middle of the hive. I timed mine with a stop watch in a trial run (stay downwind!) then used the same times inside the hive. It's important to have a bucket of water to cool the vaporiser so you get the same performance every time. I power mine off my lawn tractor with the engine running, so a partly discharged battery doesn't affect the temperature.


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## scooter58

A1B1 said:


> Like the looks of it. I read modern glow plugs heat up to 1000 degrees, would a 350 thermostat in series with glow plug affect it greatly.


Why mess with something that works ? It's only on for 3 minutes or less. I've had excellent results with mine... no mites!

Scooter58


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## DavidZ

whoops


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## larrypeterson

This is an older thread, however, I may be able to add a bit of information. Two weeks ago I mixed oxalic acid with a food grade glycerin. I heated it up to about 180 degrees F and the O/A dissolved. I was about the same viscosity as mineral oil. I used an insect fogger (Amazon) and treated just 2 hives to see what affect it might have on the bees. Last Tuesday I checked the boxes and all seemed to be well. I used the same glycerin/OA, which kept just fine and did not settle out, to treat again yesterday and today all seems to be well in the hives. As soon as the drone population starts up I plan to pull out a few larva and see if they have a higher or lower mite count.

If this method of O/A treatment is effective I plan to use it on all my colonies including nucs and maybe mating nucs. I do not have the perfect ratio yet and if anyone tries this method I would appreciate some feed back of both ratio and effectiveness. If this system works out to be effective I will be a real time saver compared to the heated battery powered cup.

Again, thank you for tolerating me, LP


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## larrypeterson

This is an older thread, however, I may be able to add a bit of information. Two weeks ago I mixed oxalic acid with a food grade glycerin. I heated it up to about 180 degrees F and the O/A dissolved. I was about the same viscosity as mineral oil. I used an insect fogger (Amazon) and treated just 2 hives to see what affect it might have on the bees. Last Tuesday I checked the boxes and all seemed to be well. I used the same glycerin/OA, which kept just fine and did not settle out, to treat again yesterday and today all seems to be well in the hives. As soon as the drone population starts up I plan to pull out a few larva and see if they have a higher or lower mite count.

If this method of O/A treatment is effective I plan to use it on all my colonies including nucs and maybe mating nucs. I do not have the perfect ratio yet and if anyone tries this method I would appreciate some feed back of both ratio and effectiveness. If this system works out to be effective I will be a real time saver compared to the heated battery powered cup.

Again, thank you for tolerating me, LP


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## dadux

Do you have a before & after mite count?
D


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## larrypeterson

dadux,

I do not do mite counts. I check the drones and from time to time when the weather permits, I sit and observe . I know this isn't the most scientific way, however, so far I think I can pretty well tell. This is the second year that I haven't had any winter losses, at least so far. It is pretty easy to extract a drone larva and examine them for mites. The mite really stands out on the white exoskeleton. I want to be really careful to just offer what works for me and not try to tell anyone else how they should raise their bees. Just because I think something or if something appears to work for me, that doesn't mean that I am right or that my ways are any better than anyone else's way. They may be much less effective.

I might have mentioned that "I snap my fingers to keep the elephants away", For the past 40 or 50 years this has worked %100 of the time. I also want to announce that "all the Indians in South America walk in a straight line, at least the one I saw did."

I wish you well, LP


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## Dusty1

I measured out a loose filling of OA into a 1/2" copper cap. on a jewelers scale came out to 2 grams. I think alot depends on moisture content in addition to how firmly you pack it.


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## JimD

Noticed on Amazon that they have a bunch of cheap units at assorted prices. Anyone tried any of these?


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## Beeboy01

Well I'm taking the plunge and am currently working on a DIY vaporizer. The heating element is a Autolite 1107 glo plug that has M10x1 threads on it. I'm using a 350 degrees high temperature cutoff switch and plan to wire in an indicator light which turns off once the acid has vaporized and the switch hits it's shut off temperature. Already have machined the heater block and reservoir and am working on the handle and wiring.I'll get some pictures posted.


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## R_V

I too enjoy building things but I don't think you can beat $69
http://www.blueridgebeecompany.com/store/p1/Oxalic_Acid_Vaporizer.html


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## Beeboy01

That is close to what I'm building but doesn't have the temperature shutoff I'm using. So far I'm into mine for about $45.00 but will have a good seven or eight hours in the build when done.


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