# Oxalic Evaporators - Electric vs Propane



## BWrangler (Aug 14, 2002)

Hi Guys,

I have been looking at the JB200 electric evaporator: 
http://www.members.shaw.ca/orioleln/Vaporizer.htm 

There are some distinct advantages to using this type of evaporator when compared to the propane heated models such as those developed by the old BWrangler.
http://bwrangler.litarium.com/oxalic-acid-vaporizer/ 

First, the operator can get away from the vaporizing process. With the propane models, the beekeeper must stand next to the device to heat it. With the electric model, distance is not a factor, only time. This would greatly reduce any operator exposure to oxalic fumes.

Second, the heat source is inside the hive and it is alot cooler than the flame from the propane torch. This would greatly reduce the fire danger from a dropped torch, etc. And the electric model could be used in situations where open flames have been restricted due to drought, forest fire danger, etc.

With the electric model, residual heat can be used in the next hive greatly reducing heating time. There's too much handling required to use the propane model while it's hot. So it takes more time to cool then heat than the electric one.

The only drawback for the electric evaporator is the weight and cost of the battery.

So will I stick with BWrangler's evaporator? It's inexpensive and works great for a few hives. But if I had lots of hives to treat, I would use the electric one.

Regards
Dennis


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## dcross (Jan 20, 2003)

I like the remote operation, but that amount of heat inside the hive makes me a little nervous.


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## Michael Bush (Aug 2, 2002)

From my point of view I didn't want to spend a lot to try it out and see how I liked it. Besides, most of my hives are regressed now and I'm not treating them, so I didn't want to invest in equipment I would soon retire. But if I were treating a lot of hives, I agree the electric model would be nice.


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## Axtmann (Dec 29, 2002)

Dennis the battery is not expensive, go to a car wrecking yard they have lots. You can even use a battery from a motorbike or ride lawnmower, they are no so heavy, as long as the battery has 12 volt. I paid 10 Euro / 12 US for one from an accident car, one year old and in perfect condition.


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## BWrangler (Aug 14, 2002)

Hummm....almost free battery. It's looking better all the time. :> )

Regards
Dennis


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## BerkeyDavid (Jan 29, 2004)

Dennis and all

I lost the link to BWrangler's web page. I want to build the "crack pipe" oxalic acid dispenser. I found some mites (first time) in some drone brood in my strongest Lang hive yesterday. 

Also interested in thoughts on the effectiveness of this method.

Plan to work my top bar hives today, maybe get more pictures.

david

[This message has been edited by BerkeyDavid (edited August 25, 2004).]


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## Michael Bush (Aug 2, 2002)

http://bwrangler.litarium.com/oxalic-acid-vaporizer/


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## wishthecuttlefish (Jun 24, 2003)

I have built the bwrangler version(s) and just used it on Monday. 

My set up allows operation from the top using a deep super over the brood chambers with a "port" hole. The first time I treated I used this method.

Then I read Axtman's old post where he indicates that doing it from the top is only 50-60% effective whereas going from the bottom is 90%+ effective.

So, on Monday I suited up, closed up my hives with paper towels and shoved the end of my gadget into the hive entrance. 

Now, advantages/disadvantages:

Doing it using a top super is easy to do. When the device is screwed into the port, little vapor leaks out of the hives. You can stay behind the hive and not worry about the bees getting pissed off. However, I constantly worried that the vapor wasn't getting down into the bottom chambers, or that it was condensing inside the top super. There certainly was a lot of condensed acid at the entrance of the port, even after extensive heating (3 minutes). I'm not sure how effective it was. 

Doing it from the hive entrance may be more effective, but it was fraught with difficulty. Firstly, bees don't like it when you shove paper towels and then a hot metal pipe into their entrance. This tends to piss them off. Combine this with an invisible white hot propane flame just 6 inches away that zaps any bees that fly through it and you have a recipe for a seriously angry hive. Next, one must be careful to immediately stamp out those paper towels when they accidently catch fire...or the landing board!! 

So, what am I trying to say? After this Monday while I feel confident that oxalic acid vapor filled the hive, I must have killed 500+ bees and I am seriously considering abandoning Bwranglers contraption in favor of a commercial electric vaporizor. Unless of course I can jury rig some used hot plate and save a buck!

Kai

[This message has been edited by wishthecuttlefish (edited August 25, 2004).]


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## Michael Bush (Aug 2, 2002)

I used the top version of TopBarGuy's evaporator last fall and again this spring and the bee inspector found no mites at all this spring. I think it worked fine. The bottom one looks too difficult to me. But I'm sure the electric evaporator probably works well too.


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## Guest (Aug 25, 2004)

I started with oxalic vapor treatments useing BWranglers hive entrance vaporizer.I didnt like having to stand in front of the entrance with a torch.The bees didnt seem to care for it much either.What I came up with is I drill a 3/8 in. hole in the back of the bottom board.There is 3/4in. between the hive floor and brood box a hole centered in that space seems to work.I plug the front with paper towels and stick the copper tube in the back.I use a wooden dowel to plug the hole .Just leave it a little long so you can get ahold of it to take it back out.


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## Guest (Aug 27, 2004)

Car batteries from a junker may be nice,
but a deep=cycle boat battery is even
better. I have several of these for
powering monitoring equipment, telescope
electronics, jump-starting balky equipment,
you name it. They recharge overnight,
and keep coming back for years.


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## Axtmann (Dec 29, 2002)

@ wishthecuttlefish and all other home made vaporizer user.

There is one important thing you should be pay attention to. 

The electric vaporizer reach approx up to 220º C / 420ºF and oxalic acid evaporated with around 180º / 350ºF.

When using a propane torch the temperature can go up to 1000ºC / 1832ºF in no time and you burning most of the acid instead of vaporizing. All you have left is some ash and probably not a very effective Varroa treatment.

Be very careful with the torch.


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## wishthecuttlefish (Jun 24, 2003)

Thanks for the advice, Axtman. I treated yesterday and used a piece of plexiglas on top so I could see what was coming out. I think that it vaporized very nicely. The empty deep super on top of the hive filled rapidly with vapor, and particles of the acid could clearly be seen coating the bees in a fine white powder. 

I'm satisfied now that treating at the top will work fine.

Kai


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## BULLSEYE BILL (Oct 2, 2002)

>I'm satisfied now that treating at the top will work fine.

Last year I made two of the top evaporizor boxes with plex covers. Attached Topbarguys crack pipes and used them. The obvious descrepancies were the different amounts of vapor coming from the pipe due to the uneven heating with the torch.

The real problem I percieved was that the vapor has a tendency to raise. Therefore, if you are going to fill the hive, you need volumous amounts of vapor to force it to reach the bottom where the most brood is and where the vapor is most needed.

Another problem I saw is that there were a lot of crystals in the mouth of the pipe and around the inside of the box around the hole where the pipe was attached. It was appearant that the acid was recrystalizing and not staying in vapor form and not reaching the bees.

While the top box was nice to watch how well the pipe worked, and you can see the bees on top get coated, I felt that it was not doing a very good job of treating the entire colony.

I treated about thirty hives with the electric unit today. If I hadn't watched my Chiefs go 0 and 3, I would have gotten them all treated.

I have a garden wagon that I use to take equipment to and from the yard with, it was useful to wheel the motorcycle battery around. I have a twenty foot extention cord with an inline light switch near the battery. After timing the amount of time needed to evaporate the acid outside the hive, (two minutes), it was a very easy opperation.

Measure 1/2 teaspoon of acid into the unit, slide it in the hive, stuff a red rag in the opening, walk to the wagon and flip the switch for 2 minutes, wait another minute to remove, and leave the rag in for a total of ten minutes while you go on to the next hive(s). By the time I had the fourth one done, I could go back and remove the first one's rag. I was doing about 12 per hour and cleaning the trays at the same time.

One problem I had was when I did not have the rag stuffed in very well and they came pouring out a bit miffed







Other than that, once the rag was removed the hive went back to normal quickly.

Second problem is to keep the screw that holds the tray on tight. It losened once and the acid did not vaporize as it should have. It was a quick fix to tighten the screw, but it would have been nice if I had a screwdriver with me.

One other thing that stood out was that the four hives that I still have deep broods on were the ones with the highest mite counts, 100+ over the week the tray was on. Some of the 100% PC hives had mite counts between 4 and 12 for a one week drop. Most had 40 to 60 for a week count.


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## Michael Bush (Aug 2, 2002)

>One other thing that stood out was that the four hives that I still have deep broods on were the ones with the highest mite counts, 100+ over the week the tray was on. Some of the 100% PC hives had mite counts between 4 and 12 for a one week drop. Most had 40 to 60 for a week count.

One possible explanation is that the deep broods are probably 5.4mm - 5.5mm cell size and the PermaComb is 5.1mm. That does result in a shorter capping and post capping time. Not as short as 4.9mm but probably shorter. I get a full day shorter for each with 4.95mm wax coated PermaComb, and 8 hours on one or the other is predicted to be enough to keep the mite population stable.


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## wishthecuttlefish (Jun 24, 2003)

I treated using the top method yesterday. I definately see the disadvantages that Bullseye talks about. The bees at the top were coated, but I saw no bees leaving the reduced entrance with any coating. 

At this point I can't afford an electric vaporizor, so I will probably continue using the "crack pipe", as bullseye so affectionately calls it. I will complete my fall treatments next weekend, doing it from the entrance. Only one of my two hives has a mite problem and I'm only treating that one. The other hive has < 5 mites dropping per day. The hive being treated has about 30 per day. 

My bottom boards (from walter kelley) are so constructed that I do not think drilling a hole in them would be a wise choice. They have a slot for the screen tray, and a lower slot for the debris tray. I might be able to get away with switching to the copper style evaporator, and hammering it so it will fit in the screen tray slot.


Kai


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## BULLSEYE BILL (Oct 2, 2002)

>I get a full day shorter for each with 4.95mm wax coated PermaComb, and 8 hours on one or the other is predicted to be enough to keep the mite population stable.

I am a little confused by your statement. For each what? And eight hours on one what or the other. Please explain, thanks.


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## Michael Bush (Aug 2, 2002)

>>I get a full day shorter for each with 4.95mm wax coated PermaComb, and 8 hours on one or the other is predicted to be enough to keep the mite population stable.
>I am a little confused by your statement. For each what? And eight hours on one what or the other. Please explain, thanks

One-day shorter capping time. One-day shorter post capping time. Total 2 days shorter from egg to emergence.

According to mathematical models of mite reproduction it has been predicted that 8 hours less capping time (from egg to capping) would result in enough change in mite reproduction to have a stable system. Also that 8 hours less post-capping time (from capped to emergence) would result in enough change in mite reproduction to have a stable system. I have only measured the times on 5.4mm cell wax and 4.95mm cell wax coated PermaComb, but considering the proportion of difference in size to times, I'm guessing that 5.1mm cell PermaComb may have as much as an 8 hour reduction in both capping and post-capping times.

This, of course is based on mathematical models. Dee Lusby's experience would suggest that 4.9mm and the full day shorter times for each (capping and post-capping times) are required for a stable system. But then there are all the variables, like mites coming in from crashing hives etc. that are hard to figure into the mathematical models that are assuming only that the mites reproduce and die at certain rates.


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## BULLSEYE BILL (Oct 2, 2002)

Have there been any indication that the mites could adjust with a shorter hatching time?

And if some is good, is more better? Perhaps 4.8?


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## Michael Bush (Aug 2, 2002)

>Have there been any indication that the mites could adjust with a shorter hatching time?

Not that I've read or heard.

>And if some is good, is more better? Perhaps 4.8?

They build a lot of 4.8mm and even large patches down to 4.6mm on their own. Dee's foundation is really an average of 4.85mm and some measurements by others of the current run of Dadant 4.9mm is about 4.85mm. The problem with 4.8mm foundation is that while small cell bees will happily use it, large cell bees will just refuse to draw it and build a lot of cross comb. They do it some already on the 4.9mm. Too bad someone doesn't make some 5.1mm, 4.9mm and 4.7mm







That would be a nice regression path with better acceptance.

And yes, the 4.8mm has been reported to have even shorter times.


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## Robert Brenchley (Apr 23, 2000)

4.7mm mills are available; I believe they're produced for scutellata. Thorne's have 4.7 foundation presses at an inflated price.

------------------
Regards,

Robert Brenchley

[email protected]
Birmingham UK

[This message has been edited by Robert Brenchley (edited September 29, 2004).]


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## BULLSEYE BILL (Oct 2, 2002)

So what is the optimium brood nest cell size if you were going to have just one size throughout the brood for small cell?


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## Michael Bush (Aug 2, 2002)

Since the "scientists" don't want to admit that EHB even make cells smaller than 5.2mm for brood, I doubt that any studies have been done. I think Dee's point is that the problems caused by the enlarged cells go away at 4.9mm and regressing is difficult for some people, so why not just go for the nearest size to what's being used that works. My guess is that 4.8 is about average brood cells. Another thing with 4.9mm is if you use it for honey too, it will extract easier than 4.7mm.

I guess that's why I'm enjoying the foundationless. I let the bees do what they want. I get them regressed on the wax coated PermaComb and then I let them build what they like and it's been interesting to watch.


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## BULLSEYE BILL (Oct 2, 2002)

Here is a picture of my setup.
http://members.cox.net/bullseyebees/_sgt/m2m2_1.htm


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## BWrangler (Aug 14, 2002)

Hi Guys,

Would the electric evaporator fit through a 3/8" hive entrance? Most commercial guys use migratory bottoms and they start out at 3/8" and get a little tighter over time.

Regards 
Dennis


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## db_land (Aug 29, 2003)

I use the JB200 - it works great but is a little flimsey. On some of my hives I have to use a hive tool to pry open the entrance a little.


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## Axtmann (Dec 29, 2002)

Bill I measured the acid with an electronic scale and it is approx 2grams. But I cant see if it is 1.9 or 2.1 grams. I think a little different thats not important. Same with the spoon they send with the vaporizer, its different if you fill it high or if you press it in or it is just even.
By the way you should adjust the tray on your vaporizer. It touches the bottom and the heat goes to the sheet metal. Nice pictures


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## BULLSEYE BILL (Oct 2, 2002)

>Would the electric evaporator fit through a 3/8" hive entrance?

Nope, mine fits through the other side, (3/4), with a little room to spare, but if the tray is heaping it will level it off.


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## dickm (May 19, 2002)

Mr Axtmann,
A friend and I (Newbee101) have used an electric vaporizer on 3 hives. Check his post on "apistan is in". Each hive got 4 treatments a week apart, completed 2 wks ago. 1 hive is successfully down to 0 mites in 24 hrs today. Before treatment it was at 60 mites in a drop.. The second had 150 mites in 24 hrs before treatment. After 4 treatments, it's still in the same range 2 weeks after treatment.
The third hive is as he described in the other thread with hundreds of mites. 
My question is: where did we go wrong? We use screen bottom boards with the board in. Pure Oxalic crystals as sold for wood bleach and the electric vaporizer. Have you or anyone else had this result with Oxalic?
I'm about to start a new round of treatment tomorrow or the next day. He went to Apistan. Thanks.

Dickm


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## Axtmann (Dec 29, 2002)

Dickm you and your friend have don nothing wrong and OA works, otherwise the hives would be dead.

<<<<<The second had 150 mites in 24 hrs before treatment. After 4 treatments, it's still in the same range 2 weeks after treatment>>>>>

There are two possibilities: 

1.	The hive has lots of brood and the mites hatching faster than you can kill them. With so many mites you should see crippled bees or bees with deformed wings. Make a test and open a few brood cells, if the mites are from your hive there must be several (4-6 or more) coming out of one cell. How often did you treat your bees last year or in early spring and what kind of medication did you used?
2.	If its hard to find mites in closed cells than the problem is somewhere in you neighborhood. I had the problem 3 years back, I found up to 2000 and more each week and there was nothing before in the drone cells (during summer). Than, during a meeting in the bee club, a guy asked me how my bees doing because he lost the bees, hi found the hives empty. He was less than a kilometer away from my bee yard.

You can see it on the amount of food the bees have, if there is more than the other colonies have (without extra feeding) your bees robbing a high infected hive somewhere.


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## magnet-man (Jul 10, 2004)

Here is a study on Electric vs Propane type evaporatiors.
http://www.apis.admin.ch/en/krankheiten/docs/saeuren/osverdampfen_e.pdf


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