# diy oxalic acid vaporizer



## rafterdog

I'm not certain how ethical it is to post this, but...
For some smaller beeks $100 or more for a vaporizer is pretty steep.
Make your own.

Drill a 3" x 3" aluminum bar stock to accept an autolite diesel engine glo plug (part #1107) and lock the heat element into the edge by tapping and inserting a #8 screw.
On the flat side drill 3/8" deep area to hold 2 tsp oxalic acid crystals. Drill and screw the aluminum piece to a 3.5" x 6" sheet metal (bend it up on the end to affix the handle). Connect the battery wires... + to the plug and - to the metal mounting plate. Put a spst switch in line with the 12v + lead. (fuse it if you want to be safe).

Viola !!! one vaporizer for about $20 bucks if you have a pretty good junk bin.

Johnny


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## JStinson

Can't see why this is unethical. Right now I have two separate tabs pulled up on my computer. One is for aluminum flat stock and one is for a Bosch 80010 glow plug. 

Thanks for the post!


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## Stephenpbird

They retail for 40 euros in Germany (e-bay) normally stuff costs much less in USA than Europe.


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## JStinson

Stephenpbird said:


> They retail for 40 euros in Germany (e-bay) normally stuff costs much less in USA than Europe.


Most here are between 90 and 150 dollars or more. There's one on ebay from the Ukraine for like 40 bucks I think. I can't imagine that it's any good.


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## beemilk

Hi rafterdog .... my mind is kinda weak right now .... due to the vodka. Gotta photo that you can post?


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## rafterdog

Beemilk... your vaporizer will be as good as your glo plug. Hey, they are cheap. /change it til you find one that works with your time constraints.
picture..? Well, just look at the excellent picture of the JB200. It's a really fine unit.


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## snl

rafterdog said:


> For some smaller beeks $100 or more for a vaporizer is pretty steep.


Not really when you consider the ongoing cost of purchasing other varroa controls. It is a one time investment and the OA itself costs just basically pennies per hive to treat.


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## mhorowit

A picture or drawing would REALLY help. Mike
Never mind. I see the picture.

How much does 2t of OA weigh?


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## cg3

mhorowit said:


> How much does 2t of OA weigh?


Pretty sure he meant 2g.


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## beemilk

I just went out and bought a digital scale from WalMart (less than 20bucks). One carefully measured teaspoon of OA checks out to be 3 grams. Measured it several time to ensure consistency.


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## vdotmatrix

OH GOODY ANOTHER PROJECT!!!

I am pretty psyched on this project and have started researching glow plugs....-probaly looking for a modern glow plug that will take a a while to heat up if there is such a thing OR else figure out what the flash point of Oxalic acid is to determine how ong to leave the glow plug connected to current.

3x3 aluminum stock sounds easy enough. 
: I know a machinist to cut out a troug and tap an area for the plug.

the rest is mechanical and trial and error.

I have not seen you post anything else on this subject so do you care to give us updates or improvements on this. It sounds a lot practical that paying $140 for one that I can safely make....
I suppose not everyone has tools, know-how or tools.
IDEAS?



rafterdog said:


> I'm not certain how ethical it is to post this, but...
> For some smaller beeks $100 or more for a vaporizer is pretty steep.
> Make your own.
> 
> Drill a 3" x 3" aluminum bar stock to accept an autolite diesel engine glo plug (part #1107) and lock the heat element into the edge by tapping and inserting a #8 screw.
> On the flat side drill 3/8" deep area to hold 2 tsp oxalic acid crystals. Drill and screw the aluminum piece to a 3.5" x 6" sheet metal (bend it up on the end to affix the handle). Connect the battery wires... + to the plug and - to the metal mounting plate. Put a spst switch in line with the 12v + lead. (fuse it if you want to be safe).
> 
> Viola !!! one vaporizer for about $20 bucks if you have a pretty good junk bin.
> 
> Johnny


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## tech.35058

I am a little behind the curve on this, still reading up & figuring out. 
I saw a guy on u-tube putting o.a. in a piece of copper tubing with one end closed & heating with a small (plumbers?) torch.
The torch I have, the scale I can get.
Where does one get oxalic acid? Are there "real " instructions/ formulas posted some where? ...


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## snl

You can get OA at Ace Hardware under the brand name "Savogran." It is wood bleach and commonly sold in the paint section. You can also get it on Ebay and Amazon.......... You vaporize one gram (approx 1/4 teaspoonful) per brood chamber......

Don't breathe the fumes!

Good luck!


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## BeeAttitudes

Anyone ever post a picture of this?


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## beepro

"Drill and screw the aluminum piece to a 3.5" x 6" sheet metal (bend it up on the end to affix the handle). Put a spst switch in line with the 12v + lead. (fuse it if you want to be safe)." 

No, it is hard to picture it. I got lost on bend it up to affix the handle. So how long is the handle? Or the handle attach to what? The aluminum bar?
And what is a spst switch? Where do I get this switch from? How do you fuse it up to what?

I might as well go with putting 3 drops of OA onto a piece of small printer paper strip to burn it underneath the hive on top of a removable bottom aluminum cloak board.
Burn a strip a day to keep the mites away.


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## Rader Sidetrack

An "spst" switch is a "single pole single throw" switch. Basically an on-off switch that has only two wire connections/terminals. 

An ordinary wall light switch is an example of an SPST switch. If it were a so called 'three way' light switch, then it would be a 'SPDT' switch (single pole double throw) with 3 terminals. (We are not counting the frame 'ground' screw as a terminal.)

Typical commercial OA vaporizers have a wattage of around 150 watts. At 12 volts, that means a switch would be expected to handle around 13 amps, so you should look for a switch that is rated for at least that in amps. Note that those commercial vaporizers often do not have a switch and just use spring battery clamps instead. (The above is intended as background information only.)


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## crofter

2 tsp is a way more than a dose for a double deep; about 4 times what is recommended. The volume of the pan though, will have to be much larger than the volume of the powder you put in otherwise as it bubbles up during the liquifying stage it will overflow and part of the charge lost. Some of my original ones were too small in this regard. The model below is also too high to go in a standard entrance plus the body of the glow plugs should be separate from the pan on their own mount (heatsink) You may make a few before you get all the bugs worked out.


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## FlowerPlanter

I too tough 100 bucks for a piece of aluminum and a glow plug is a little much. So I made my own.
Used a copper pipe and glow plug in one end very simple but had to have a power source. 

Didn’t want to hull around a battery. So I sealed one end of a pipe and heat it with a propane torch, by far the simplest/cheapest vaporizer. Not much to carry around from hive to hive. 

I was planning on making one out of stainless but decided not to treat instead.


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## FlowerPlanter

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

Here is a very simple design. 
You can even skip the fittings to make it even simpler.


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## snl

FlowerPlanter said:


> I too tough 100 bucks for a piece of aluminum and a glow plug is a little much.


It' a one time cost. And thereafter is let's than $.10 per treatment. Compare that to other treatments that you have to buy over and over and I think you'll see it's a bargain.......


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## Tony Rogers

Let's challenge ourselves to come up with one that we can make for under $30.00
Could we perhaps make one out of every day parts found in a hardware store, without the need to weld anything or mill out a cup?


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## beepro

O.k. then. That is the easy challenge. Here is my little mite strip experiment.
Put some water into a few table spoon of OA. Then take some small paper strips to dip
them in. After the strips are dried put them under the removable bottom board to burn into the hive.
The bottom board has a 2" shim line with heavy duty aluminum foil at the bottom for a clean
burning. Light a few strips every time you are out there to get rid of the mites. Saw this one on
you tube vid. Nothing to drill or screw onto. You think this is doable?


Cheap OA:


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## FlowerPlanter

>Let's challenge ourselves to come up with one that we can make for under $30.00
It's already been done. YouTube is full of DIY OA ideas; cost me .50 worth of pipe.

>After the strips are dried put them under the removable bottom board to burn into the hive.
The bottom board has a 2" shim line with heavy duty aluminum foil at the bottom for a clean
burning.
This is a new approach.


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## Fishman43

beepro said:


> After the strips are dried put them under the removable bottom board to burn into the hive.


I would be curious to know if the fire/burning didn't cause a chemical change/degradation of the OA
Below is a link to the combustion equation of Oxalic Acid, in a prefect chemical reaction (open fire under a hive is not) you would only get CO2 and water:

https://answers.yahoo.com/question/index?qid=20090429182817AAwQqXE


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## Rader Sidetrack

Also, the sublimation* temperature of oxalic acid is 147 degrees C (297 degrees F), while the temperature at which paper burns is much higher (papers vary, but think of _Farenheit 451_).


I'm not a chemist - or a chemical _engineer_, but that might be a concern.

*(sublimation is the process of turning a solid into a gas without going through a liquid phase)


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## beepro

Well the burning experiment had failed!!!!!!!!
Why? Because apparently OA in powder form does not dissolve in water that well. So another approach maybe needed like
mixing with essential oil or something. OA sprinkled on paper does not burn well either. It solidified after got in contact with the fire.
But I found a better way: 
I got it! Cost less than .10 cents to burn. And only took 30 seconds to see the vapor for a 
complete 2 minutes of clean burn (1 teaspoon of OA) using this process. No electricity is necessary using everyday household materials. 
I dare not to publish it afraid to put the oav gadgets out of commission. Got cough a little more than I wanted for not wearing
my respirator. Got 2 mins of vid on it while burning and lots of good pics too. Yes, I do see the spiky crystals also. It works!


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## pmshoney

ford 7.3 L powerstrokes take glowplugs I have installed lots of them over the yrs tried autolight and others they seem to blow up kinda with a pop sound when over heated even the bosh but the factory motorcraft you can buy even in the parts stores are are a couple bucks more but are self regulating and last a lot longer when running them continuous with out using glow plug timer relay


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## Fishman43

Beepro that is like saying I have video proof showing pots of gold at the end of rainbows but won't publish them for fear of putting the gold miners out of business. If it is really so easy share, and help everyone


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## Barry

beepro said:


> It works!


Prove it.


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## archerman

Where can I find a block of aluminum to make this with? I searched all my junk stuff and can find nothing. 
Thanks


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## Headnut

Archerman
Here's a pic of one I made.
If you will P M me I have lots of alum plate 1/2" thick free to you, I 'm not too far from you I'm in west Ga off I 20.


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## beepro

Headnut, I like your slim oav version. Very professional done.
Mind giving the dimensions of each pieces? i.e. the block, drill size use, etc.
And where the negative terminal is connected to? I only see the hot wire connect to
the plug.


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## rookie2531

beepro said:


> Headnut, I like your slim oav version. Very professional done.
> Mind giving the dimensions of each pieces? i.e. the block, drill size use, etc.
> And where the negative terminal is connected to? I only see the hot wire connect to
> the plug.


I believe he has the neg. Wired at the end of the all thread and wood handle. I put mine there also, but no wood handle on mine.


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## Headnut

Drawing.


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## BudsBees

What size and number 
is your glow plug


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## Headnut

Budsbees
My glo plug is a Autolite 1104.
Someone .suggested a Motorcraft for a Ford power stroke.


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## BeeAttitudes

Using a propane torch as the heat source would be nice as its a lot of heat and lighter than a typical battery. The downside of the torch designs above is that you can't see the OA while heating it to know when you are done. Glass holds up well to heat. Maybe a small paint bottle with a decently thick wall would make a good reservoir. If one could find a small jar with a threaded neck and then get an air tight connection to a pipe, you would have a cheap and user friendly design. Just unscrew the jar to refill.

Or maybe one of those test tubes with a cork in the opening with a tube running through the middle of the cork.


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## Rader Sidetrack

Rader Sidetrack said:


> Also, the sublimation temperature of oxalic acid is 147 degrees C (297 degrees F) ...


I made an error in the sublimation temperature of oxalic acid in post #25. The temperature in the document is 157 degrees C, which converts to 314.6 F.


Source document: http://www.cdc.gov/niosh/ipcsneng/neng0529.html


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## erlaita

Hello,
I am a newcomer; must excuse me if I make some foolish question.
I've been watching the projects that are in the forum to build a vaporizer oxalic. My first question is about the material: aluminum is suitable as a container for holding the boiling acid? It is not corroded by acid? I thought using stainless, but it is much harder to do machining at home. I prefer to use aluminum, if there are no drawbacks.


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## snl

erlaita said:


> Hello,
> I am a newcomer; must excuse me if I make some foolish question.
> I've been watching the projects that are in the forum to build a vaporizer oxalic. My first question is about the material: aluminum is suitable as a container for holding the boiling acid? It is not corroded by acid? I thought using stainless, but it is much harder to do machining at home. I prefer to use aluminum, if there are no drawbacks.


No foolish questions here. Aluminum is just fine and it is what is used by most and no, it is not corroded by the OA. Stainless is better as it allows a more even distribution of heat but you'll be just fine using aluminum.


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## EastSideBuzz

I have 2 and will run them off a 12 volt motor cycle battery. Lets me do one side of a pallet at a time. I think that I can drive 4 off of one battery on apposing pallets. so I am looking to expand to 8 at a time.

I bought them from the guy here in the states that sells them.


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## Scpossum

I built mine and paid around $25 for the aluminum. That bought enough to make about 5-6 units. Then with glow plug, scrap handles, wire, and clamps each will come out to be around $20-25 bucks. Order aluminum stock off of ebay. Hardest thing is hollowing out the acid "bowl" for me.


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## Headnut

SCpossum I know what you mean about making the acid bowl. What I did the four I made I laid out the bowl then drilled four holes in the corners then milled it out on this old milling machine just don't drill the holes all the way through the bottom.


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## beepro

No, the aluminum will not react with the OA. Maybe this is a weaker acid. 
I have made a simple small bowl out of the heavy duty aluminum foil. 
Then use a small candle flame to burn off the OA at the
hive bottom with a 2" hole thru the bottom board. The hive must use shims to
raise it so the bees will not get burn too. After a few tests run I got it. And the
mites are dropping like flies after the first 2 rounds of treatment. I use 1/2 teaspoon
per nuc hive. And time it to 3 minutes then removed the flame. 
It works though very primitive method for a small scale hobby hives.


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## rookie2531

beepro;120628l the burning experiment had failed!!!!!!!!
Why? Because apparently OA in powder form does not dissolve in water that well. So another approach maybe needed like
mixing with essential oil or something. OA sprinkled on paper does not burn well either. It solidified after got in contact with the fire.
But I found a better way:
I got it! Cost less than .10 cents to burn. And only took 30 seconds to see the vapor for a
complete 2 minutes of clean burn (1 teaspoon of OA) using this process. No electricity is necessary using everyday household materials.
I dare not to publish it afraid to put the oav gadgets out of commission. Got cough a little more than I wanted for not wearing
my respirator. Got 2 mins of vid on it while burning and lots of good pics too. Yes said:


> Did you mix it with drano? Also, I don't think it worked, if you see a small version of superman's house.


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## beepro

It works! The small shiny white OA crystals consolidated on my nitrile glove during the test
burn. When burning at the hive the fumes went all over the hive with some escaping
out the crevices too. I saw dead mites today. Did a treatment on last Sat and again yesterday.
Will do one more tomorrow. The bees seem o.k. after the OA burning. Mite level had decreased
significantly inside the hive. And did not mixed in with anything either, no drano only the OA powder.
Will be interested in when you can make better improvements on my primitive burning method. Already
got a better way devised for this process. Can you?


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## Rader Sidetrack

Here is another technique for you to try, _Beepro _... 



Daniel Y said:


> On the subject of untested ideas. Here is a poor mans method of OAV. Get a small metal cup. Walmart has some for about 99 cents for 4. place a lit hooka coal in it and then put a dose of OA on a piece of aluminum foil. Place that on top of the frames of your hive. cover it and walk away. you can come back in an hour or two or the next day and remove the cup. Not my favorite way to do it and you do not get that really great cloud like you do with the vaporizers. but it does work. I still keep coals and cups on hand. if I am running short on time during one of my scheduled treatment days I can grab those coals lite them all with a torch. drop them in the cups with a small pair of tongs. get the OA doses set up and drop them in the hives. I can treat 20 hives this way in about 10 minutes. When I get back from whatever. I can go back out and remove the cups.


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## erlaita

Hello,

I have another question about the homemade vaporizer: is the *temperature control*.

- 1) The water of hydration leaves at 101.5 ° C (214.7 ° F) The water boils off leaving anhydrous oxalic acid crystals.
- 2) At 157 ° C (314.6 ° F) the oxalic acid starts to sublime (Directly goes from solid to gas)
- 3) *At 189 ° C (372.2 ° F) the oxalic acid which has not yet sublimed decomposes to formic acid and carbon monoxide*.

You do you use a temperature control system in your DIY vaporizers to prevent decomposition of oxalic?


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## nater37

Thanks for all the input guys


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## erlaita

Hello,
I've been looking at some thermostats operating in the range of vaporization of oxalic. There are two components used in appliances, perhaps, could be used in the vaporizer:

Electric iron thermostat:








Deep fryer thermostat:


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## oldfordguy

I just tore apart my wife's iron last week and got the thermostat out of it and am in the middle of building a vaporizer to see how this works out.


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## nater37

Will Ac work with Dc current? I notice that both these pets are Ac components. If you are building an Ac unit, I would be afraid to use it in the field so to electrocution.


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## erlaita

I do not think there is any danger: the thermostat has a metal contact, which would be to cut a 12V DC voltage.


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## snl

Actually using some of your "inventiveness" for a possible new vaporizer......thanks and good luck with yours!


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## crofter

AC thermostats and circuit breakers are not designed for DC. Direct current tends to arc momentarily when circuit is broken and metal gets transferred from one contact to the other (pitting) I have played with them in making egg incubators. They work for a while and then fail to initiate contact on temperature drop.


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## tech.35058

crofter said:


> AC thermostats and circuit breakers are not designed for DC. Direct current tends to arc momentarily when circuit is broken and metal gets transferred from one contact to the other (pitting) I have played with them in making egg incubators. They work for a while and then fail to initiate contact on temperature drop.


Maybe those of you thinking Electric should consider using a rheostat (?) ( variable resistor) for control. I would monitor temp using the non-contact thermometer I bought for my day job ($25 at harbor frieght) but if I had to go buy the thermometer for this project,, that might exceed the cost to just buy a store bought unit?
I like the idea posted by DanielY in another thread, & quoted above about putting a coal in a cup, putting oa in a tin foil over it & walking away. I dont like the idea of setting my hive on fIre though 
some one said they used 1/2 teaspoon of oa to treat a hive ... I got out my new scale I bought at walmart for under $20, set it to metric scale, enough sugar to see what 1 gram of sugar looked like.
sugar is 1/2 teaspoon per gram with this device.maybe I should measure the wt. of 4 teaspoons & divide, since this won't measure smaller increments than 1 gram. this might be 1.99 gram for all I know. I checked google for grams to ounces conversion, 28.xxxx grams per ounce.
I ordered 2 pounds oa from ebay, ($12, including shipping) should show up this week.
I guess I would _like_ a device a could carry from hive to hive like a smoker, stick the nozzel in the entrance & puff x number of times, or turn on a battery operated fan for x number of seconds, then move on to the next. I only have 4 , no 3 hives at home ( one died) & 3 at my mothers house, so I am really small scale. would be nice if the parts were something that worked for other uses too, not just once per year. batteries used once a year blah blah.
just dreamin'.


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## seapro220

I agree with both sides ..

A one time cost then it's $.10 per treatment, but with about $20 in parts - that's a whole lot of treatments at $.10 each hive. Other treatments aside, as we all know/try to follow those also - but $125 or $165 ???


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## mgstei1

Testing one now without a PID controller but simply using the burn cup mass to keep temp below 350degF and the heating device below a 5 amp current draw @ 12vdc and only pulling 50 watts.(2g burnoff @<5min)
Also, have a compounder developing a safer delivery method for the OA.
Will be American made and hopefully American made parts. Still researching 1 item made overseas(China) and may be outa luck on availability here.


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## crofter

I did a OA weight in using my reloading powder scales in grains and did the multiple conversions. Tech. you might be advised to do 10 charges and divide if your scale has that coarse of graduations. Just from memory I came to the conclusion that half a teaspoon was a bit more than 2 grams but is what I use for a double deep.

I had the thought that it would be nice to have OA pellets of approx. 1 gram that you could drop down a snap cap covered tube into the temperature controlled pan. This way you would not have to cool the evaporator between burn offs. Probably the recreational drug boys could point us to a suitable pill maker and an anti hygroscopic coating for our mite pills!


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## mgstei1

crofter said:


> I did a OA weight in using my reloading powder scales in grains and did the multiple conversions. Tech. you might be advised to do 10 charges and divide if your scale has that coarse of graduations. Just from memory I came to the conclusion that half a teaspoon was a bit more than 2 grams but is what I use for a double deep.
> 
> I had the thought that it would be nice to have OA pellets of approx. 1 gram that you could drop down a snap cap covered tube into the temperature controlled pan. This way you would not have to cool the evaporator between burn offs. Probably the recreational drug boys could point us to a suitable pill maker and an anti hygroscopic coating for our mite pills!


Compounder working on it now for 1/2, 1 and 2 g pills. The pill manufacturers want to use a lubricant for their machines to spit em out cause the OA crystals are I guess different, and I have refused to accept them with a lubricant. I have a small pill maker that is 8mm in diameter and can turn out several a minute but the pill makers can do thousands. I had planned on putting them in push out plastic pill dispensers so exposure to the acid would be less than using a scoop. They are available in Europe in a bottle but shipping is costly compared to manufacture here.
Anybody out there work in a pill manufacturing facility ? I talked with one in New England and the least they would set up for is a 1 ton run and their machines required lubricants.


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## crofter

Well, there you go! I am a day late and a dollar short with my idea. It would be nice to have a quicker way to get a measured dose into multiple hives without the uncontrolled blowing around and unmeasured delivery of some of the commercial versions we have seen videos of. I am happy with the bare bones models but do not ever plan to get big (and spoil my fun)



mgstei1 said:


> Compounder working on it now for 1/2, 1 and 2 g pills. The pill manufacturers want to use a lubricant for their machines to spit em out cause the OA crystals are I guess different, and I have refused to accept them with a lubricant. I have a small pill maker that is 8mm in diameter and can turn out several a minute but the pill makers can do thousands. I had planned on putting them in push out plastic pill dispensers so exposure to the acid would be less than using a scoop. They are available in Europe in a bottle but shipping is costly compared to manufacture here.
> Anybody out there work in a pill manufacturing facility ? I talked with one in New England and the least they would set up for is a 1 ton run and their machines required lubricants.


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## mgstei1

whats that ol saying in the union shop ?
Give the nastiest, sorriest, hardest, most difficult that the brightest and best employee has tried to do to the sorriest, laziest, no count employee, and he/she will find the easiest, best, cheapest way to get it done. 

I'm lazy and have worked around hazardous chemicals all my life as an Instrument/Electrical Journeyman in most of the chemical plants along the Texas coast and still hate being exposed to them. 
I wear gloves and a respirator and sometimes a face shield if the bees will let me using the OAV. Get a mean spirited lady under a plastic faceshield and the sound and nearness is unbearable.
OAV works and works well on mites. How it don't bother the girls is beyond me. But chemicals have always fascinated me on how you can make, apply or swallow something so good outa something so bad to start with, is way beyond me.


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## Vince

Will a vaporizer work if you have screened bottom boards?

Vince


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## snl

Sure a vaporizer will work with SBB. However, you need to get a piece of aluminum flashing or heavy duty aluminum foil to cover it. The covering does not have to be perfect.......... either of those items will work just fine. I believe the flashing would be easier to manipulate but you probably have heavy duty aluminum foil in your kit cabinet.........


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## nater37

Just got through making 4 of them using HeadNuts drawing. Looks great, have to be a little careful as block is .50 thick and the glow plug is .475 so no room for error. I will try it in the morning to see how it does. I guess I need to get a timer and do a dry run to see how long to leave in hive.


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## Dyzio

Hi,
Red wire is connected to glow plug about black? to handle rod? The hole for handle is drilled thru? 
I can't see it on any pictures.

chris


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## nater37

Dyzio said:


> Hi,
> Red wire is connected to glow plug about black? to handle rod? The hole for handle is drilled thru?
> I can't see it on any pictures.
> 
> chris


Yes, I put double nuts on the 5/16 all thread and grounded there. The black goes in the yellow connector in picture. I did not have wired in pic.


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## snapper1d

One question.How do you keep from blowing the glow plugs? I have tried two glow plugs and they heat up for a few seconds and you hear then spit and they are shot! I thought I would just try this little project this morning and made one with some copper pipe.A 4" piece of 3/4" copper pipe split and flattened.Then rolled up the long ends.One to fit the 5/16' all thread and the other to fit the glow plug.The other ends I used a hack saw and made a couple cuts next to the rolled ends so as to have a flap to bend up to make the cup.Used a little solder to fill the cut gaps.It didnt take long at all.The only problem is shorting the glow plugs after only a few seconds.


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## vdotmatrix

nater37 said:


> Just got through making 4 of them using HeadNuts drawing. Looks great, have to be a little careful as block is .50 thick and the glow plug is .475 so no room for error. I will try it in the morning to see how it does. I guess I need to get a timer and do a dry run to see how long to leave in hive.


 Man I love the opportunity to jump in and make one of these things....I just have so many sticks in the fire right now and I will probably have to just suck it up and buy one.... but I am going to save this post so I can make one anyway before springtime or copy the one I buy... Thanks!!!


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## snapper1d

Here is the one I made this morning and it was really easy.Now if someone can tell me about why it blows glow plugs in only a few seconds.


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## vdotmatrix

Hey do you have a side view of this puppy? Perhaps it the wrong glow plug....now you are making me want to play with this and try to make one!!!!! nice jwork snapper


snapper1d said:


> Here is the one I made this morning and it was really easy.Now if someone can tell me about why it blows glow plugs in only a few seconds.
> View attachment 15772


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## crofter

Most likely a plug not designed for 12Volts. Some are designed to be supplied through a voltage reducing controller of the vehicle. Also common on a lot of homemades is that the body of the plug is mounted into the heated tray. Have a look at a plug and you will see the internal parts are insulated from the shell by a type of plastic. When screwed into an engine head the mass of the cylinder head keeps the body of the plug a lot cooler than when it is in a vaporizer with a temperature around 350 F. Not ideal! Only the hot tip of the glow plug should contact the tray.


----------



## snapper1d

Here is another pic.To bend those edges up to make the pan all I used was a crescent wrench.














Crofter I was wondering about the tip of the glow plug being in contact with the metal plate but I couldnt tell in the pics of others if that was the way they had done it.How about it others are your tips contacting the pans?


----------



## rookie2531

The one I made does. The tip slides in the drilled hole and, I have a set screw that comes in from the side to clamp it tight to the vap. Pan.

It was a little big, so I used 2 glow plugs.

http://www.beesource.com/forums/showthread.php?304935-homemade-oav


----------



## snapper1d

Would you think one would be enough for this pan I made or would I need two.I saw one similar to what I made on youtube and his has only one.


----------



## crofter

I enlarged the pan on one model because if found that during boil off some of the oxallic liquid overflowed and got wasted. With only one plug the larger pan was a bit slower to finish vaporizing. It is important to have good contact between the pan and only the heating tip of the glow plug. The set screw system like what rookie did is the simplest.Below is a snip from another thread of another method.
_Dave H
Re: homemade oav
The heating element in mine is a very tight fit. I had to heat the aluminum with a torch and put the glowplug on ice to get it in position. My thinking being that a tight fit means a more effective transfer of heat. _

The body of the plug should not be in tight contact with the tray as that would be a heat loss and not healthy for the glow plug.


----------



## mathesonequip

snapper1d said:


> One question.How do you keep from blowing the glow plugs?


some automotive applications used 6 volt glow plugs or something else, you only want to use 12 volt ones with a 12 volt battery. you need good contact from the tip to the bowl. you really do not want to heat the threaded part of the glow plug space it back. glow plugs are designed usualy for hot side red [positive], but reversing the leads makes no difference.


----------



## BigGun

By your pic it looks like the side of the plug is what is in contact with the pan. You want the plug below the threads to contact the pan. In other words the hot part of the plug should be in contact with the pan and not the threads or body above it.


----------



## snapper1d

Your threaded part is your ground.Without a ground you have no circuit.No circuit no heat.


----------



## rookie2531

nater37 said:


> Just got through making 4 of them using HeadNuts drawing. Looks great, have to be a little careful as block is .50 thick and the glow plug is .475 so no room for error. I will try it in the morning to see how it does. I guess I need to get a timer and do a dry run to see how long to leave in hive.


I'm loving it, maybe you can sell 2 and make a little cash. Good job.

As far as snapper says for ground, I did end up touching the threads to a heat sink and the all thread and my ground wire is connected near the handle. I'm not sure if that affects heat up time but it works for me.


----------



## snapper1d

Your all thread is much bigger than your ground wire so it shouldnt affect it one way or the other.


----------



## 78-79fordman

Here's one I'm building to use the 7.3 ford glow plug since I run trucks with this plug mite as well use it . Still got to cut the cup out .


----------



## nater37

rookie2531 said:


> I'm loving it, maybe you can sell 2 and make a little cash. Good job.
> 
> As far as snapper says for ground, I did end up touching the threads to a heat sink and the all thread and my ground wire is connected near the handle. I'm not sure if that affects heat up time but it works for me.
> 
> View attachment 15827
> View attachment 15828


I do need 11 more deeps with foundation, I may have to barter


----------



## rw willy

Some vehicles use a glow plug controller to moderate the voltage to the glow plug. Without this they will blow! I believe the Bosch 80010 has a built in controller. Not sure if other models do, KI am not a glow plug expert. Just putting it out there. Hopefully someone can elaborate.
good luck


----------



## BeeAttitudes

Erlaita, to address your question, I'm wondering if a temperature switch might be the lowest cost solution to control the temperature in the range needed. PID or on/off controllers are much more expensive.

Here is a temperature switch that's rated for 15A and seems to kick on/off at appropriate temperatures. At about $8, it's not too expensive. It would turn the heat element off at 169C (336F) and kick it back on at 157C (315F) which should work for this application.










http://www.alliedelec.com/white-rodgers-3l11-325/70101866/#tab=specs





erlaita said:


> Hello,
> 
> I have another question about the homemade vaporizer: is the *temperature control*.
> 
> - 1) The water of hydration leaves at 101.5 ° C (214.7 ° F) The water boils off leaving anhydrous oxalic acid crystals.
> - 2) At 157 ° C (314.6 ° F) the oxalic acid starts to sublime (Directly goes from solid to gas)
> - 3) *At 189 ° C (372.2 ° F) the oxalic acid which has not yet sublimed decomposes to formic acid and carbon monoxide*.
> 
> You do you use a temperature control system in your DIY vaporizers to prevent decomposition of oxalic?


----------



## erlaita

BeeAttitudes,
crofter said:


> AC thermostats and circuit breakers are not designed for DC. Direct current tends to arc momentarily when circuit is broken and metal gets transferred from one contact to the other (pitting) I have played with them in making egg incubators. They work for a while and then fail to initiate contact on temperature drop.


In the datasheet I saw that specifies 120VAC, 240VAC; I think it should be discarded such switc. We must find a controller that operates at 12VDC


----------



## BeeAttitudes

My guess is it would last a long time switching 12V DC current as long as you don't exceed the 15 Amp rating. I wouldn't be afraid to use it.



erlaita said:


> BeeAttitudes,
> crofter said:
> 
> In the datasheet I saw that specifies 120VAC, 240VAC; I think it should be discarded such switc. We must find a controller that operates at 12VDC


----------



## crofter

BeeAttitudes said:


> My guess is it would last a long time switching 12V DC current as long as you don't exceed the 15 Amp rating. I wouldn't be afraid to use it.


AC Thermostats

Some caution is needed if you're using a thermostat not specifically designed for this sort of application. Most thermostats, and other switch gear, is designed for use with AC and relies on the current disappearing every 10 milliseconds or so, as the 50 or 60 Hz AC current changes direction, to stop an arc being drawn. If used with a high current DC source (even one which is well within the current rating of the switch) the arc will tend to persist burning out (perhaps welding shut) the contacts pretty quickly which would be a bad thing. 



You could try it; it might last for quite a while. I found the contact degradation destroyed the precise accuracy needed for an egg incubator. There is a lot of design difference in AC and DC thermostats and circuit breakers. The current carrying capacity is not the issue so much as the arc over effect at every occasion the unit cycles.


----------



## BeeAttitudes

I agree crofter, it will reduce the cycle count which is normally 100,000 cycles. So it might be reduced to what.....20,000 cycles? That would still last a while and if/when it fails, replace it for less than $10. Also, when it fails it will likely fail closed which may cause the vaporizer to overheat till you switched it off (or disconnect it from the battery or maybe it pops the glow plug). How big a deal is that? Again, replace it and possibly replace the glow plug it burnt out.

I still think it would be fine for a homemade vaporizer. The alternatives are to find a similar temp switch that is rated for switching roughly 15 Amps of 12V DC power and get it cheap (if it's not cheap, you might as well purchase a factory unit). So far, I haven't been able to locate one (hopefully someone will and will post a link here). If we don't locate one, it seems this one will work fine.

FYI, I called the mfg and spoke with their design engineer. This was designed for AC use and they recommend it for AC use.......but they do have a few customers that use this design to switch 12V DC power (he mentioned a seat warmer in a vehicle). He said it would definitely reduce the cycle count but he couldn't say by how much without extensive testing switching a similar load. So he can't recommend it without specific testing.

So while not ideal, it will work. If it only holds up for 10,000 cycles....that is a lot of treatments.......especially for a hobbyist. Does anyone have a better/cheaper solution to keep the temperature in the ideal range?

Edit to add: PM me and I can supply the engineer's contact info


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## mathesonequip

skip the thermostat like everybody else does.. run it thru a couple of cycles outside the hive with a watch. then do what works, as the battery goes dead it will take longer to heat by a little bit. it is not like the oxalic acid is real expensive, if you get it too hot, you get some formic acid which is the treatment for tracheal mites. you are over-thinking this. just figure out how long it takes to vaporize the crystals, cool it a set amount of time and repeat.


----------



## Vince

I made a video that shows how I made my vaporizer and how I did my treatment.

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

Vince


----------



## snapper1d

Real good video Vince and a class A+ job.The only thing is 99% of us have no cnc machine nor know how to even use one.I think people need to see how to make one with limited resources."a poor man's vaporizer".


----------



## Vince

snapper1d said:


> Real good video Vince and a class A+ job.The only thing is 99% of us have no cnc machine nor know how to even use one.I think people need to see how to make one with limited resources."a poor man's vaporizer".


I realize that most people do not have access to a CNC machine. But one of the reasons for the video is to show the inner workings of the vaporizer. I use the tools I have at hand. BTW, building/rebuilding CNC machines is another hobby of mine. 

Vince


----------



## snl

Vince said:


> I realize that most people do not have access to a CNC machine. But one of the reasons for the video is to show the inner workings of the vaporizer. I use the tools I have at hand. BTW, building/rebuilding CNC machines is another hobby of mine. Vince


Vince,
Perhaps you could make and sell the pans to folks who like to take it from there and make their own? Just a thought.


----------



## BeeAttitudes

Vince, a few questions if you don't mind.

- What volume is your cavity that holds the OA powder? And does it seem large enough to hold and vaporize 3g of OA without spilling while boiling (even if not perfectly level)?

- What size is the AL block?

- I see you did some temperature testing. What was the max temp the AL block reached with the glow plug running?

- Finally, do you know the amperage (or wattage) of that glow plug?

Thanks!


----------



## beepeep

The simplest I have found. A 12"-18" long 1/2"copper pipe with one end smashed close. Pour in the dose. Gently and evenly heat up the pipe with propane torch. Use a pair of vise grips for a handle.



FlowerPlanter said:


> https://www.youtube.com/watch?v=ALHz4B1vqKo
> 
> Here is a very simple design.
> You can even skip the fittings to make it even simpler.


----------



## BeeAttitudes

Beepeep, that is simple. After reading about how nasty this stuff is, I don't want that close when it turns to vapor.


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## kramerbryan

Beepeep, that is a simple way. I made one and the realized I was spending too much time on my knees with a torch. Electric ones allow you to do something else while it is working, and keep away from the vapor. I cheated though and bought one. Thanks SNL.


----------



## BeeAttitudes

I was able to answer a few of my own questions (a couple still unanswered).

I re-watched the video and you stated the aluminum block was roughly 1" x 1.5". Judging from the 1/2" thickness I would guess the size closer to 1.5" x 2". I'm still curious the dimensions of the cavity for OA and if you think it is large enough for 3g treatment without boiling over while evaporating (which seems about the max that would normally be used).

I looked up the glow plug you used (Autolite 1107) and it is the same as a Bosch 80034 or an AC Delco 60G. the AC Delco 60G is rated at 170 Watts so at 12V DC that is roughly 14 Amps. I would guess the Autolite and Bosch plugs use a similar wattage. FYI, these plugs are rated for 11V.

I like your compact design. I would sure be helpful to know the max temperature the aluminum block reaches when the glow plug is left powered on. I seen you had an infrared temp measurement tool in the video so I hope you can share that information. Will it get up over 400F?

Thanks again!



BeeAttitudes said:


> Vince, a few questions if you don't mind.
> 
> - What volume is your cavity that holds the OA powder? And does it seem large enough to hold and vaporize 3g of OA without spilling while boiling (even if not perfectly level)?
> 
> - What size is the AL block?
> 
> - I see you did some temperature testing. What was the max temp the AL block reached with the glow plug running?
> 
> - Finally, do you know the amperage (or wattage) of that glow plug?
> 
> Thanks!


----------



## drmimiky

Vince, Thanks for the video. I do not have access to a machine shop, only do some woodworking. Would you consider making the aluminum tray with the mill work done and selling them? I could do the rest of the work. Thanks Mary [email protected]


----------



## TimW

What are people using for glow plugs? There are 2 different ones being mentioned here: Autolite 1104 (headnut post #36) and Autolite 1107 (Vince video post #91). One is 11v and the other is 6v.

According to Napaonline.com:

Part Number: ASP 1104
Product Line: Autolite Spark Plugs
Attributes:
Glow Plug Electrical Rating : *11 Volt, 140 Watt*
Glow Plug Hex Size : 12 mm
Glow Plug Thread Size : 12 mm
Terminal Type : M5 x .8


Part Number: ASP 1107
Product Line: Autolite Spark Plugs
Attributes:
Glow Plug Electrical Rating : *6 Volt, 53 Watt*
Glow Plug Hex Size : 3/8"
Glow Plug Thread Size : 10 mm
Terminal Type : M10 x 1

I'm designing my block to use the 1104 using a 12mm tap to hold the glow plug. Once I have it done and know that it works, I'll post the drawing with dimensions.


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## BeeAttitudes

I think the Autolite 1107 was replaced by the 1115.

A 10mm plug fits a 1/2" block much better than a 12mm one will if that is what you are using to build the vaporizer. The Bosch 80034 is 10mm and its rated at 11V. I didn't find a wattage for the 80034 but for it's AC Delco equivalent, the 60G AC Delco, is rated for 170W (roughly 14 Amps at 12V). So I'm thinking that would work nicely.

Here is info on the Bosch 80034:

https://www.boschsparkplugs.net/product.aspx?zpid=16007


----------



## BeeAttitudes

I finally found some 1/2" Aluminum plate this week and bought it. Haven't yet started but here is a drawing of what I'm thinking of making. 

First, a drawing showing the size of the block with dimensions. Note that after all the drilling/tapping is complete, then the bottom portion of the block is cut off (shown in the cross-hatched area):









After the handle mounting block is cut away from the main block, then it would look similar to this after assembly:
Correction to drawing: 8x32 screws are 1.25" long......not 1.75" as shown in drawing. Also note that it would likely be easier to place the jamb nut for the all-thread handle on the opposite side of the handle mounting block (facing the handle). that would make it easier to access the 8x32 jamb nuts that hold the handle block tightly (I'm assuming the holes for the 8x32 screws would be drilled out so that an 8X32 bolts slides through).









Hopefully using a separate block for mounting the handle will prevent a lot of heat transfer to the all-thread rod used for a handle. And I hope the thermo disk mounted of the opposite side of the cavity from the glow plug heat source will allow the block to get 10F above the working heat range of the thermo disk (315F - 336F). 

I show a separate wire running back up the handle from the outlet side of the thermo disk. This would be to power a light mounted in the handle so you would know when the glow plug is powered on. My thought is that you would time how long it takes for the OA to evaporate after the light turns off the first time (meaning the aluminum block is up to temp). This way, you wouldn't have to cool down the block all the way in between hives for your timing to be accurate. So no matter if the evaporator is heated from 70F or 200F, you let the evaporator run the same amount of time after the evaporator is up to temperature. Might save a little bit of time between hives (maybe).


----------



## BeeAttitudes

An updated drawing showing the correct length on the 8x32 screws and showing the jamb nuts in place for the 8x32 screws which I left off the previous drawing. Only thing not updated on this drawing is that I would move the 5/16" x 18 nut to the opposite side of the handle mounting block (so it is on the side of the block nearest the handle). This would allow easier access to the 8x32 jamb nuts for tightening.


----------



## erlaita

Hello,

I have a problem in my tests of vaporization: oxalic that begins to evaporate, recrystallizes on the edges of the pan, sometimes forming a kind of thin dome. 

I do not know why that is. Perhaps because the temperature is too low?


----------



## crofter

Yes, too cool; it would vaporize if it were hot enough.


----------



## erlaita

Hello,
I have another question: There are two ways to put the oxalic in the pan 
1. put oxalic when the pan is cold and wait for it to warm: It may take time depending on model
2. Take the pan always connected and hot, put the oxalic and enter immediately into the hive, so it is faster because it does not cool.
What is the correct way?


----------



## nater37

erlaita said:


> Hello,
> I have another question: There are two ways to put the oxalic in the pan
> 1. put oxalic when the pan is cold and wait for it to warm: It may take time depending on model
> 2. Take the pan always connected and hot, put the oxalic and enter immediately into the hive, so it is faster because it does not cool.
> What is the correct way?


Cold


----------



## crofter

As nater37 says, cold is the recommended and safest way. If you are doing a succession of hives and time is crucial, you can off power and only partially cool the vaporizor before charging. A bit like throwing dynamite with a lit short fuse! You might save 30 seconds.

Leaving the pan powered up and dumping in a fresh charge would be off the scale of bad practice!


----------



## snl

erlaita said:


> Hello,
> I have another question: There are two ways to put the oxalic in the pan
> 1. put oxalic when the pan is cold and wait for it to warm: It may take time depending on model
> 2. Take the pan always connected and hot, put the oxalic and enter immediately into the hive, so it is faster because it does not cool.
> What is the correct way?


#1 is the correct and really only way you should do it.......... However, you do not have to wait until the pan is warm to place it in the hive. Put the OA in a non heated "pan," then just place it in the hive to vaporize...


----------



## vdotmatrix

OKAY MAN...whwnever you guys think you have a winning design PLEASE post the specific Shopping list so I can get started already,


----------



## Brad Bee

I'm interested in this thread. I'm currently TF on all hives but I want to do some testing on OAV. I want to set aside some hives and treat them with OAV and compare them with my TF hives. My bees come from stock that's been untreated for 20 years so I want to see how much effect Varroa has on them.

By the way, we use a good bit of aluminum at my shop. I have some 1/2" plate that I can shear to approximate size needed if someone wants some. We'll work out a fair price and I'm not looking to sell large quantities of it. I know I have some 1/2" plate drops but not an abundance. Probably enough for 20 vaporizers. One 4' x 8' sheet of 1/2" 6061 T-6 aluminum is extremely expensive but if someone wants enough of the pieces I will entertain making them. I do not have a milling machine but I can get them milled if someone wants them that way, but understand they won't be cheap to make.

AND, like vdotmatrix posted, someone please post a shopping list when you guys get this hammered out. I have no idea what a thermo-disc is or how to wire one up.


----------



## Denniston

I'm super excited for all this information on this thread.

I'm not familiar with glow plugs, and what I'm seeing is that some people seem to think that you should not thread the glow plug into the piece of aluminum that your well is machined out of. I.e. the threaded part of the glow plug should not be in contact with anything hot. Is that correct? If I regulate the heat with a thermo disc will that keep the heat low enough? If the threaded part is not to be in contact with the "pan" if you will, has anyone though of using an insulator? Maybe a plug PTFE that fits tightly into a hole and then is drilled and tapped to accept the 10mm glow plug?

I also read somewhere that only the tip should be in contact with the aluminum plate. Can someone explain to me what is mean by the tip. Is that the tip of the slender part of the glow plug or is that the entire slender part of the glow plug. What I'm thinking is that if that entire slender part is in contact with the aluminum it would transfer the heat faster. Or is it important for that part of the glow plug to not be in contact with the aluminum?

Last thing, since I'm just getting prepared for keeping bees, I'm not sure if a 3/4" thick aluminum plate will work? I ordered a couple of pieces of it, before I realized that everyone was using 1/2". (it can be hard to judge scale from the pics). Any way will that fit in the opening? Will that be too much mass to heat up?

Thanks in advance.


----------



## vdotmatrix

I went ahead and bought the RJ200 kit or whatever it was and try to duplicate it from a working model...but kepp up the good work.....


Denniston said:


> I'm super excited for all this information on this thread.
> 
> I'm not familiar with glow plugs, and what I'm seeing is that some people seem to think that you should not thread the glow plug into the piece of aluminum that your well is machined out of. I.e. the threaded part of the glow plug should not be in contact with anything hot. Is that correct? If I regulate the heat with a thermo disc will that keep the heat low enough? If the threaded part is not to be in contact with the "pan" if you will, has anyone though of using an insulator? Maybe a plug PTFE that fits tightly into a hole and then is drilled and tapped to accept the 10mm glow plug?
> 
> I also read somewhere that only the tip should be in contact with the aluminum plate. Can someone explain to me what is mean by the tip. Is that the tip of the slender part of the glow plug or is that the entire slender part of the glow plug. What I'm thinking is that if that entire slender part is in contact with the aluminum it would transfer the heat faster. Or is it important for that part of the glow plug to not be in contact with the aluminum?
> 
> Last thing, since I'm just getting prepared for keeping bees, I'm not sure if a 3/4" thick aluminum plate will work? I ordered a couple of pieces of it, before I realized that everyone was using 1/2". (it can be hard to judge scale from the pics). Any way will that fit in the opening? Will that be too much mass to heat up?
> 
> Thanks in advance.


----------



## beepro

So where can I go to buy this kit? Why not the entire completed OAV set up? Is it too
expensive and the kit is cheaper. 

As long as the 3/4" will fit thru the entrance it will bee fine. You can always add the extra shim onto your hive bottom
board to make it higher so the 3/4" will fit in. Either that or cut the aluminum thinner.


----------



## vdotmatrix

I was dying waiting for a working prototype all winter and i am an impatient mofo so i pulled the trigger...


beepro said:


> So where can I go to buy this kit? Why not the entire completed OAV set up? Is it too
> expensive and the kit is cheaper.
> 
> As long as the 3/4" will fit thru the entrance it will bee fine. You can always add the extra shim onto your hive bottom
> board to make it higher so the 3/4" will fit in. Either that or cut the aluminum thinner.


----------



## snapper1d

Denniston some will tell you the threaded part will rob all your heat but that threaded part is not much bigger than two 1/2" nuts so it cant rob hardly anything.Some will also tell you that you dont want the threaded part to get hot but they dont think about how much heat it is receiving when it installed in a hot running engine.The tip being in contact with your pan will definitely transfer heat much better.


----------



## beepro

vdotmatrix said:


> I was dying waiting for a working prototype all winter and


For a $35 dollar difference I would just buy the entire completed unit.
Anyways, you got what you wanted. Rather than waiting for a working prototype I gather my
creativity to make a stationary unit for my tiny bee set up. This working prototype has the potential
to put the now electric unit out of business so I did not publish it thinking that not to ruin others oav business here.
Yep, something too creative and overboard can bee dangerous too. Now the mites are dying and I'm winning this battle for the time being.
I have never seen a healthier bee hatch every time in a long time now.


----------



## Arackis

So I have a CNC programer and someone set up to make some of these. It looks like most of you guys are wanting a DIY kit but do not have the tools to do the machining. I can have the machined block and handle made. It would also accept the Autolite 1104 glow plug. I'm just curious if I were to do this how many of you would be interested in purchasing one? Let me know what you think and if you would prefer a different glow plug or any other ideas or suggestions.


----------



## beepro

Welcome to Bee Source, Arackis!

At the time being, I have no interest to purchase one yet.
Because I have made a stationary set up under the hive to do the OAV.
Very effective to get rid of the mites and not too costly at all. Thanks though.


----------



## Arackis

Thanks I have been a long time lurker and have been learning a lot from you guys. This place is a wealth of knowledge.


----------



## erlaita

Hello,
about the glow plug I have a couple of questions: I think all plug here have mentioned Hex size = 12mm, it makes the vaporizer can not be introduced into a 10mm entrance. It is a problem for me. There are a glow plug Hex size = 10mm, that would be perfect. But I do not know what more precise characteristics heater need: I think it would hold a voltage between 11V-12V. Must be dual coil type: having two heating elements, this enables the glow plug to have any available "self-regulating" feature. The glow plug need any other particular feature?
Perhaps the wattage would have to be close to the 150w?


----------



## Arackis

Thank you for your input I will look for a 10 mm glow plug that meets those specifications. If you find one before I do please let me know.


----------



## Arackis

The AC Delco 60 G is dual coil and self-limiting also the hex measures out at 9.5 mm. From what I'm reading on the diesel forums one guy left it on for eight hours and it still worked. I may pick one of those up and test it out.


----------



## erlaita

How many volts needed?


----------



## Arackis

10.5V and 170W so is should be perfect


----------



## erlaita

We hope the results of your assembly. 
I think this glow plug is used in USA, but not in Europe. How could I find something like this?


----------



## EastSideBuzz

I bought a few locally for 165 or so. He marks them up $50 each. So I suggest getting them from outside of the USA and they are only 109.


----------



## beepro

I wonder if it is economic feasible when the glow plugs cost almost as much
as the completed OAV unit on the market today?
I thought the purpose of the DYI is to save us some money here. I would just buy the
unit instead if it wasn't for the stationary oav set up already. Have fun!


----------



## Arackis

The glow plugs here in the US are less than $10. Can you European guys get glow plugs for a 1989 General Motors 6.2 diesel?


----------



## Arackis

Or if you guys know of an inexpensive European glow plug less than 12 mm and fits the discussed specifications let me know. We can to build it that way as well? I'm just having a hard time finding European glow plugs and information on them here in the US.


----------



## Rader Sidetrack

The Bosch 80010 12 volt glow plug is used in both commercial and homemade vaporizers - here is a thread regarding that:
http://www.beesource.com/forums/showthread.php?288482-Homemade-oxalic-acid-vaporizer

The Bosch Company is based in Germany, and its products are distributed worldwide. I would be very surprised to find that Bosch glow plug products aren't available in Spain.


----------



## Arackis

It looks as that plug is at least 12mm or larger. Some were saying that 12mm is too large for their hives?


----------



## Arackis

erlaita said:


> We hope the results of your assembly.
> I think this glow plug is used in USA, but not in Europe. How could I find something like this?


I think I will also offer the glow plug for sale as a separate item for those who need them.


----------



## desotohemi55

http://www.beesource.com/forums/showthread.php?288482-Homemade-oxalic-acid-vaporizer/page4 post 64

$2 copper vaporizer pot for glow plug


----------



## erlaita

Hello,
elsewhere on this forum I read that copper is not desirable,
http://www.beesource.com/forums/archive/index.php/t-273419.html



> *Axtmann*
> Use a rust free steel pipe or aluminium and not copper. If you're not cleaning you copper pipe very careful you will have copper acetate in your next treatment. This is very healthy when the fumes come in contact with your honey.


oxalic can produce poisonous copper compounds (copper acetate)
I'm no expert, but would have to clarify this point.


----------



## desotohemi55

I haven't seen a lot of info on this using of copper and have seen others using it in different ways. The temperature for copper acetate to fume is 464F i believe, which should leave any in the bowl as residue, but yes, clean it good. I would think very little if any would get into the hive, and the bees would remove any like they do the acid crystals. As far as being toxic, Oaxlic acid rates higher than copper acetate. The supered honey should have been removed anyway. I would like to hear more feedback on using copper for the pot though, im no chemist.


----------



## popeye

Here is my completed copper vaporizer. snapper1d has a thread about making one. I added a aluminum brace to keep from tilting sideways. Also a heat shield under it. May not need the shield but wasn't sure what it would do to screen over my oil pans. Which I may just pull the pans and vaporize from the rear under the screens. Works like a champ when doing test vaporizing. I spent about 15$ on it. Had to buy Autolite 1104 plug and clamps at auto part store. Rest was scrap material on hand.


----------



## giarc18

I just finished building my oav using a Bosch 80024 . the guy behind the counter said this was the equivalent of the autolite 1104. It Burned out on the first trial run . it got nice and hot , and after about 10 seconds , crackled and burned out. 
Maybe this was a defective one, but I'm not gonna buy the same one and find out.
Definitely request a self regulating glow plug when you go the the auto parts store. 
Ch


----------



## Ski

Ok This sounded like a fun project so I went to a local machine shop and had the aluminum block drilled tapped and a welled out.
I started with a sketch from Beesource and after discussions with the machinist I ended up with something a bit different .
The block ended up being 2 inches long 1-3/8 inches wide and 5/8 inches thick I used the 1104 autolite glow plug and a ¼ -20 threaded rod.
I ran the unit dry twice for ten minutes each time and that burned all the machine oil off.
I then put 2-3 grams of OA in the well. It took 1 minute for anything to happen and then was all over at about 4.5 minutes. I figure it took a bit longer since there is more mass to the aluminum block then some of the other units. I ran the unit twice with similar results.
Anyway I think it’s a workable unit and I would not have it if everybody had not shared that they had done, Thank you for sharing.


----------



## giarc18

Ski were you able to find the 1107 in stock somewhere or did you order it? None of my local stores seem to stock this plug. I don't want to keep experimenting with different plugs at $10 bucks a pop. The bosch i tried burned out 10 seconds into the first trial run. 1107s seems like the plug that most are using, so it must work. 
Ch


----------



## Ski

I used the 1104 and did not look for the 1107.
I did get the 1104 from O'Reileys. They did not have it in stock but got it in a few hours.


----------



## giarc18

OK thanks, I misread your post.
No oreileys by me though.
Maybe I'll check around for the 1104
Ch


----------



## brettj777

How large of a battery is needed for this? I am getting a vaporizer that uses the glow plug. A 12v auto battery would work, but that's alot to lug out into the field. I only have 6 hives.

Any recommendations on the size of battery appropriate for that? I can charge it in between....obviously dont wanna run out of charge when treating!

thx


----------



## popeye

I think you could use a lawnmower/motorcycle/ATV type battery too. Test it first and see if evap time is different.


----------



## giarc18

I don't see why not as long as the battery is in good condition. I plan on using my ATV as my power source. 
Should have enough capacity to do 3 or 4 hives easily without needing recharge if the battery is good to begin with.. If you have to jump start your lawnmower or ATV I wouldn't even bother. The battery is no good.

BTW I settled on an autolite 1115 glowplug. It cost a little more but it self regulating and it passed my first round of trial runs. I let the parts guy talk me into another plug on my first run because it "cross referenced" to another plug. It burned out in the first 10 seconds.


----------



## aunt betty

I made a vaporizer out of 1/2" copper pipe. Soldered a couple 90's on so it would stay in place. The last piece I left un-soldered so I can dump a dose of powder in and cap it before heating with a torch. Have never done oxalic acid vapor on a hive. There has to be a drawback. I hear it's hard on queens. True or false?


----------



## snl

aunt betty said:


> Have never done oxalic acid vapor on a hive. There has to be a drawback. I hear it's hard on queens. True or false?


You heard incorrectly. You may be thinking about MAQS.


----------



## mathesonequip

it is my understanding that oxalic acid vapor is safe for queens and has a good safety margin. oxalic acid dribble or drip can lead to severe queen damage with strong or repeated treatments, the liquid form treatment should be used only with caution.


----------



## Daniel Y

erlaita said:


> Hello,
> 
> I have another question about the homemade vaporizer: is the *temperature control*.
> 
> - 1) The water of hydration leaves at 101.5 ° C (214.7 ° F) The water boils off leaving anhydrous oxalic acid crystals.
> - 2) At 157 ° C (314.6 ° F) the oxalic acid starts to sublime (Directly goes from solid to gas)
> - 3) *At 189 ° C (372.2 ° F) the oxalic acid which has not yet sublimed decomposes to formic acid and carbon monoxide*.
> 
> You do you use a temperature control system in your DIY vaporizers to prevent decomposition of oxalic?


What most fail to understand is that he OA turned to gas at 157 degrees. it does not have a choice to stick around for the 189 degree temperatures. you would have to contain it and force it to be subjected to those temperatures. it would also be a gas at that point unless it was under pressure. The OA will turn to gas and leave the heat source at 159 degrees. at that point it does not matter what temperature your heat source is. the OA is no longer exposed to it. the heat source can be 2000 degrees. When the oa reaches 159 it gasses off end of story.


----------



## 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


----------



## aunt betty

I'm using the can from a throat lozenge package. It's exactly the right size. My wife watched the video and provided the can. Had a flip top and everything. All you need is threaded rod, wire, the battery, and the diesel igniter coil. 

My chemical free beek friends are appalled that I would even consider using (gasp) chemicals in a bee hive. 
Uh...honey is a chemical. So is sugar, iron, zinc, titanium oxide, and wood. (all found in a "chemical free" bee hive).
Chemical free beekeeping is an oxymoron.


----------



## giarc18

I'd be interested to hear how the tin can works.
. I think an alluminim block acts as a heat sink. It heats up slower and holds the heat for a little bit, allowing the oa to vaporize good. 
I think you might experience problems with a tin can. Let us know how it works out. 
CH


----------



## mathesonequip

auntbetty did not mention that a small amount of oxalic acid is always present in honey.


----------



## aunt betty

giarc18 said:


> I'd be interested to hear how the tin can works.
> . I think an alluminim block acts as a heat sink. It heats up slower and holds the heat for a little bit, allowing the oa to vaporize good.
> I think you might experience problems with a tin can. Let us know how it works out.
> CH


gee you're smart. I think, maybe...50/50.


----------



## mathesonequip

aluminium is a great heat conductor it quickly spreads the heat evenly.


----------



## snl

Daniel Y said:


> What most fail to understand is that he OA turned to gas at 157 degrees. it does not have a choice to stick around for the 189 degree temperatures. you would have to contain it and force it to be subjected to those temperatures. it would also be a gas at that point unless it was under pressure. The OA will turn to gas and leave the heat source at 159 degrees. at that point it does not matter what temperature your heat source is. the OA is no longer exposed to it. the heat source can be 2000 degrees. When the oa reaches 159 it gasses off end of story.


Exactly, no need for temperature control!


----------



## waynesgarden

snl said:


> Exactly, no need for temperature control!


Wouldn't a temp controller extend the charge of a battery, allowing more hives to be treated on a single charge? 

Wayne


----------



## crofter

As long as there is product left in the tray it will not go appreciably above the boil off temperature. The temperature control then will function to keep it from getting any hotter than set point but will not permanently break the circuit. I dont see much savings on input energy as opposed to manually disconnecting to cool. 

Is the temperature control thermostat a solution to a non existent problem?


----------



## snl

waynesgarden said:


> Wouldn't a temp controller extend the charge of a battery, allowing more hives to be treated on a single charge?
> 
> Wayne


Possibly. But you're disconnecting the vaporizer shortly after OA has reached the vaporization point.


----------



## mathesonequip

i agree with snl. i hope our friends do not impose energy efficentcy regulations, the amount of power saved would not amount to much.


----------



## erlaita

Hello,
I would like to clarify one point: when I made the first prototype, the hollow of the pan was narrow and high, and I had a problem again sublimated oxalic crystallize forming a dome supported by the upper edges of the pan. So I think it's better a lower and wider gap.

You have not had any similar problem?


----------



## Daniel Y

waynesgarden said:


> Wouldn't a temp controller extend the charge of a battery, allowing more hives to be treated on a single charge?
> 
> Wayne


NO only better energy transfer will reduce energy required to raise the temp of the OA more efficiently. otherwise a cooler temp will just take longer. The energy use will be a wash. YOu sitll have to have some way of knowing how much time is needed to vaporize the OA otherwise you will be wasting energy.


----------



## Daniel Y

erlaita said:


> Hello,
> I would like to clarify one point: when I made the first prototype, the hollow of the pan was narrow and high, and I had a problem again sublimated oxalic crystallize forming a dome supported by the upper edges of the pan. So I think it's better a lower and wider gap.
> 
> You have not had any similar problem?


I have experienced the same problem with a couple of my designs. the vapor cannot contact any part of the vaporizer that remains cooler. You want the entire pan to heat up or the OA will just recrystallize on it. We had this problem with the tea light cups if you use more than one gram at a time. the answer for a two gram dose was to use two cups. Saw the same thing with the use of stainless steel pipe and copper pipe. A shallow wide pan seems to avoid this problem the best. The vapor cooling and crystallizing while suspended is the idea you are shooting for.


----------



## johnmckeag

Oxcalic acid was always present in honey. Perhaps the use of the vapors would increase the presence?


----------



## aunt betty

To do a large number of hives in a day a guy could use one of them cheap two cycle generators. The one I own has a plug for twelve volts and another for 110. Its small and an old man like me can carry it with one hand.


----------



## dobbs

ok i scrolled and scrolled and may have missed it but is anyone using a steel pan? i have a welder and can weld any thickness of steel. but dont have alum or the tooling to cut it. also has anyone used one of those soldering irons that used to be used for soldering cast iron septic pipe? 
oh and i am new to the thread but it is nice to see everyone talking bees.


----------



## dobbs

also no one is talking about the high heat in side the hive. some of my bottom boards are painted and clearly there is wax in a hive... isnt there fire danger?


----------



## rookie2531

Headnut said:


> Drawing.


I used this drawing to make one. It is a bit bigger than the drawing and the milling of the dish is rounded corners. It only took 2:00 min to start and by 2:20 was over. But a percentage of it spilled out. Not too many shooting stars, but one blob all at once spilled out.

How can I improve this so it won't happen? Cut more of a dish out? Make the block bigger, smaller? I think maybe this design has too deep dish and not enough surface for when it begins to vapor on bottom and the top is still powder.


----------



## aunt betty

I've been following the OA treatment wave as close as I can. Built a vaporizer and have never used it. Been doing more research and found that beeks in Europe use approximately a 3% OA solution do douse their bees with. They apply it using a syringe and basically shoot 5ml of solution between each frame onto the bees. Takes about 40 ml per hive body and is 100% effective at killing the adult varroa mites.
I'm not biting yet and am treatment free but am exploring the possibilities.

One of the large bee supply companies has the license to sell an OA product to use on honeybees in the USA and we should be seeing it soon (I heard).


----------



## Rader Sidetrack

_Aunt Betty_, be aware that an oxalic acid 'dribble' method is somewhat more harsh on the bees than a vapor treatment. Generally, using the dribble method is recommended no more than once per year.

You may be interested in Randy Oliver's page on this: http://scientificbeekeeping.com/oxalic-acid-questions-answers-and-more-questions-part-1-of-2-parts/


----------



## snl

aunt betty said:


> One of the large bee supply companies has the license to sell an OA product to use on honeybees in the USA and we should be seeing it soon (I heard).


The large bee supply company that is now selling OA is Brushy Mountain. They will only sell to those who live in the states that have approved OA. The BM website frequently updates that state listing.


----------



## kengineer

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


_ think this is the best https://www.youtube.com/watch?v=_Z_3RjvLT44

I guess it's like life, some want to make it more complex than it needs to be, it can be so simple, or utterly complex._


----------



## Daniel Y

I hate to see an OA Product being produced. As it is there is no regulation on OA by the federal government. Start producing a product and there will be.


----------



## snl

Daniel Y said:


> I hate to see an OA Product being produced. As it is there is no regulation on OA by the federal government. Start producing a product and there will be.


Care to restate that? OA was approved for use in beehives by the EPA back in March....... or did you mean something else????


----------



## Rader Sidetrack

And of course, EPA approval of oxalic acid for treating varroa means that there are now a number of regulations to go with that approval. That includes 'label directions' that carry the force of Federal law. Links to all of that are available here:
http://www.regulations.gov/#!docketDetail;D=EPA-HQ-OPP-2015-0043


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## Daniel Y

Approval is not regulation. I showed along time ago what the epa's decision was concerning OA. It is exempt from regulation. start making pesticides out of it and it won't stay that way. Ya gotta slit the hairs when talking gtovernment. and approval means approval regulation means regulation. you won't find those words under the same definition in the dictionary.


----------



## snl

Rader Sidetrack said:


> And of course, EPA approval of oxalic acid for treating varroa means that there are now a number of regulations to go with that approval.


Actually, the regs are minimal............


----------



## Rader Sidetrack

Daniel Y said:


> Approval is not regulation. I showed along time ago what the epa's decision was concerning OA. It is exempt from regulation.


Oxalic acid (used as a pesticide) is NOT exempt from regulation. _Daniel Y _espoused that opinion long before the EPA approval but he was wrong then. And in this issue it doesn't matter what the dictionary says - what counts is what is in the CFR (_*Code of Federal Regulations*_).


----------



## Daniel Y

Graham, Provide the documents that support your opinion. I have. I have not been able to find any documents concerning OA as a pesticide so I am not sure what findings you are basing your opinion on. OA was considered as a disinfectant. Now if you make a pesticide out of OA it will then be subject to the same regulations as any pesticide, and that is my point. OA as it is is no more a pesticide than powdered sugar. Regardless of the effect it has on mites.


----------



## Rader Sidetrack

DY, I posted a link to the documents on the EPA oxalic acid decision back in post #175 earlier this morning. 

Here is that same link again: http://www.regulations.gov/#!docketDetail;D=EPA-HQ-OPP-2015-0043

At that page you will find a series of supporting documents available. For instance, this one is for the EPA proposed/approved product label with oxalic acid _pesticide _application instructions:
http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2015-0043-0018

You may find this line on that _pesticide _label of interest ... 


> It is a violation of Federal law to use this product in a manner inconsistent with its labeling.


----------



## Daniel Y

So according to the EPA's ruling what label is required? The one you linked to is a draft of a proposed label. Not the final label required. The other links with the exception of one are similarly information. descriptions and proposed regulations for teh EPA to consider. but what where the actual final regulations that are imposed?

I said long ago the EPA exempts OA from regulation. You are correct that this decision was not made in regard to OA as a pesticide specifically because OA had not been used as a pesticide. You claimed that if it where approved as a pesticide it would be subject to the same regulation of any pesticide. is is those blanket regulations I am asking you to provide. I have never seen them.

Now that the EPA has ruled on OA as a pesticide specifically what exactly is there final ruling? what are the regulations it is subject to? As I read it the ruling is Unrestricted approval. No label, no requirements. unrestricted. Now what was that I said there ruling was long ago? Exempt from regulation.

I am still waiting to see these "Same regulations that apply to all pesticides" you keep mentioning. I have always thought that each individual pesticide has it's own unique set of regulations and requirements.

Now OA is considered a pesticide by the EPA which it was not before. at worst it was recognized as a disinfectant. One that was no longer in use. 

More importantly was my point that the EPA did not consider OA a pesticide any more than they thought powdered sugar is even though both are used to control mites in a honeybee hive. Now they do. they have approved it as such without restrictions. but I still consider it a step back that they consider it a pesticide at all.


----------



## aunt betty

The law that you must worry about is the federal one that says you can not use a product for anything other that what is on the label. Many reasons for this. 

For instance suppose you go to the paint store, use the wood bleach in your OA vaporizer that you made in the garage...you accidentally dose yourself and end up in the E.R. with a bill to pay and I'm betting you'll want your insurance provider to pay it. That is when their lawyers parade around the fact that you mis-used a product and used it not according to labeling. 

Them laws are there to protect you and the system from people who could harm themselves by not reading and following instructions on the label.

Arguing about how the EPA said it's ok at the point where you've blinded yourself isn't much help.


----------



## Rader Sidetrack

Daniel Y said:


> So according to the EPA's ruling what label is required? The one you linked to is a draft of a proposed label. Not the final label required. .....


The way it works is that the EPA provided a 'sample' approved label with their decision. But the EPA does not manufacture or sell the actual pesticides themselves (in this case oxalic acid). It is up to the manufacturer/vendor to prepare the label for their product and get it approved by the EPA before putting it on the market. If a vendor was _smart_, I'd think that they would make their label very similar to the EPA sample label.

Brushy Mtn is one outlet selling oxalic acid labeled as a pesticide for varroa control: 
http://www.brushymountainbeefarm.com/Oxalic-Acid/productinfo/727/
(Note that Brushy will only ship to states that have also approved the product. See the link.)

I'm not going to regurgitate the EPA ruling details here. Read the links I provided if you want the final details.


----------



## Fairplumber

kengineer said:


> _ think this is the best https://www.youtube.com/watch?v=_Z_3RjvLT44
> 
> I guess it's like life, some want to make it more complex than it needs to be, it can be so simple, or utterly complex._


_

How do you keep the immersion heater from burning out ? Isn't it supposed to be submerged in liquid ?_


----------



## kramerbryan

I have been experimenting with the immersion heater. I took a half inch copper cap and wrapped it with a piece of 1/2 copper that I split down the side, using it as a shim. I did 16 hives before it failed, somewhere in the coil. I paid $9 for it so it was still cheaper than other methods of treatment. I also own a Varrox, but it has recently failed and I was looking for a cheap alternative. If you only have 1 or 2 hives the immersion heater would suit you well.


----------



## Fairplumber

Ok thanks , I made one the other day but I jammed a 3/4 cap down in the coil I may have been to hard in the cool it boiled water real quick in a test run and treated one hive then tried a second hive and it failed . I was wondering if the glow plug type would last longer . I may just make one out of copper pipe and a removable resivor for the OA and heat with a torch


----------



## Caleb E

This might be dumb but why couldnt you just dissolve the OA in water and then run it through a fogger?


----------



## Galaxie

Caleb,
It's because we want the OA to sublimate into a gas. As a gas, the OA will condense into pure microcrystals all over the hive, bees, and mites. With a fogger, I imagine it would be more like a scattershot OA dribble.


----------



## Rader Sidetrack

If you want to mix oxalic acid with water, tests have determined that mixing it with sugar water (syrup) and distributing it with a garden sprayer is an effective method of mite control. See Randy Oliver's page on the OA "dribble" method: 
http://scientificbeekeeping.com/oxalic-acid-questions-answers-and-more-questions-part-1-of-2-parts/

Note that OA vaporization carries certain inhalation risks for the beekeeper, and is relatively slow if you have a large number of colonies to treat. The dribble method has lower human risks, and is faster, but should not be applied to the 'same' bees more than once, as there is higher risk for the colony with multiple dribble treatments to the same bee.

.


----------



## Caleb E

Galaxie said:


> Caleb,
> It's because we want the OA to sublimate into a gas. As a gas, the OA will condense into pure microcrystals all over the hive, bees, and mites. With a fogger, I imagine it would be more like a scattershot OA dribble.


Thank you. See, I knew there was a reason no one had already thought of this.


----------



## mathesonequip

brand new bee ideas are quite rare.


----------



## mjl328

mgstei1 said:


> Compounder working on it now for 1/2, 1 and 2 g pills. The pill manufacturers want to use a lubricant for their machines to spit em out cause the OA crystals are I guess different, and I have refused to accept them with a lubricant. I have a small pill maker that is 8mm in diameter and can turn out several a minute but the pill makers can do thousands. I had planned on putting them in push out plastic pill dispensers so exposure to the acid would be less than using a scoop. They are available in Europe in a bottle but shipping is costly compared to manufacture here.
> Anybody out there work in a pill manufacturing facility ? I talked with one in New England and the least they would set up for is a 1 ton run and their machines required lubricants.


What amp would I need to get for my vaporizer battery?I built one myself and want to try it out this weekend.Who sells them?thanks


----------



## JeronimoJC

Question for anyone knowledgeable; 
If the post below is correct, then can a person "burn" an aluminum foil package containing OA inside the smoker? 



Daniel Y said:


> What most fail to understand is that he OA turned to gas at 157 degrees. it does not have a choice to stick around for the 189 degree temperatures. you would have to contain it and force it to be subjected to those temperatures. it would also be a gas at that point unless it was under pressure. The OA will turn to gas and leave the heat source at 159 degrees. at that point it does not matter what temperature your heat source is. the OA is no longer exposed to it. the heat source can be 2000 degrees. When the oa reaches 159 it gasses off end of story.


----------



## crofter

You would have a problem with recrystallization in the nozzle of a smoker and and unknown amount of the charge would not make it into the hive.

The post you quoted makes some analogical associations that are not completely so. Even radiated heat from the suppose much hotter surface _may_ raise the temperature of the vapor above the point where it is subject to decomposition into formic acid, carbon monoxide and water which would be considered a problem. A controlled temperature not too far above the sublimation point ~ 315F. is the target most of the patent evaporators reach with different methods to prevent too much overshoot. 

Even the crude crack pipe evaporator creations recommend a gentle overall heating to prevent hot spots or recrystallization.


----------



## JeronimoJC

Thanks for explaining that Frank!

One more question; What is wrong with some crystallization (say a copper pipe)? Wouldn't that be somewhat okay provided the majority of the OA is evaporated?


----------



## erlaita

Hello,
*Frank crofter* has spoken wisely in my view. My evaporator 150W, made with a glow plug in aluminum pan works like this: a 100°C starts to boil oxalic, to 160°C begins to evaporate, and to 200°C is when all the oxalic disappears. Everything that happens between 90-120 seconds. Therefore, it does not seem appropriate to use hot air guns or gas heaters,are too strong.
For temperature measurement I use these inexpensive "K type" thermometers (5 Euro in China )


----------



## JeronimoJC

Erlaita, honestly, I don't really understand why the statement I quoted above and posted here ==>>http://www.beesource.com/forums/showthread.php?288693-diy-oxalic-acid-vaporizer/page8&p=1263414#post1263414 doesn't apply or it isn't accurate. For now I am content with differing opinions on this. 

My next question has to do with crystallization. Not to be rude, but to get to the point: *So what if there is some crystallization?* Please help me understand what is so bad about this. I get that you won't have the entire dosage evaporated, but that's not a big deal is it? 

Thanks!


----------



## erlaita

In my opinion, the re-crystallization is a problem that occurs when the oxalic vapor cools too quickly (or when the heating is too slow), and crystallized oxalic is accumulated at the edges of the pan, or nearby objects. For treatment to be effective, the vapor must penetrate all areas of the hive, and should solidify into tiny crystals that are deposited on all surfaces and on bees.


----------



## crofter

In the case of the crack pipe comparison, the amount that crystallizes in the snout short changes the dose actually administered and if the next usage inputs a bit more heat the previous leftover gets added to the current one, which then gives a greater dose. Really oxalic vapor is quite flexible in its safety margins but guessing is not the best approach.

The suggestion of putting the oxalic acid into a packet of aluminum foil and throwing it into the smoker would be rather unpredictable. Surrounding on all sides changes the heat input pattern from what it would be when heated in an open pan. The possibility of superheating a gas above its atmospheric pressure evaporating temperature is very confusing to some people. The result is likely of very little concern to most reasonably designed devices of around 125 watt input but the possibility exists to reach decomposition temperatures if the pan were to be heated hot enough to "sear" the charge. 
I see some devices are thermostatically controlled to eliminate any chance of overheating. I think this is a bit of overkill but the decomposition point is definitely to be avoided. The quip in the last sentence of the quoted post has the words "end of story" is a bit dismissive, no?


----------



## viesest

crofter said:


> but the decomposition point is definitely to be avoided.


Decomposition also is not critical. All chemicals of decomposition are known and in quantities of 1 gram are not an issue. And if temperature of heat source is to hight OA will sprinkle. The whole thing can bi reduced to: if sublimation is not very rapid and finishes in 2 minutes the temperature of heater is fine.


----------



## JeronimoJC

viesest said:


> Decomposition also is not critical. All chemicals of decomposition are known and in quantities of 1 gram are not an issue.


I am glad you brought this up. I am no chemist, but it makes sense to me that there is an appreciable difference in decomposition between heating large quantities vs. small quantities.


----------



## JeronimoJC

crofter said:


> In the case of the crack pipe comparison, the amount that crystallizes in the snout short changes the dose actually administered and if the next usage inputs a bit more heat the previous leftover gets added to the current one, which then gives a greater dose. Really oxalic vapor is quite flexible in its safety margins but guessing is not the best approach.


Thanks for addressing my question. I tend to agree with your take on crystallization. If I were to use the crack pipe method I suspect I would first try to avoid cristallization, by heating the entire pipe and I would clean the pipe after every use. Most importantly, I would try to avoid overheating.


----------



## crofter

viesest said:


> Decomposition also is not critical. All chemicals of decomposition are known and in quantities of 1 gram are not an issue. And if temperature of heat source is to hight OA will sprinkle. The whole thing can bi reduced to: if sublimation is not very rapid and finishes in 2 minutes the temperature of heater is fine.


Two minutes after the OA powder liquifies until the sublimation is finished would be about right. If you are familiar with the particular units habits you can cut power before completion and let it coast for the last part.

Two grams is the dose for a double deep.


----------



## viesest

crofter said:


> If you are familiar with the particular units habits you can cut power before completion and let it coast for the last part.


I recently became aware of that.


----------



## Daniel Y

crofter said:


> Two minutes after the OA powder liquifies until the sublimation is finished would be about right. If you are familiar with the particular units habits you can cut power before completion and let it coast for the last part.
> 
> Two grams is the dose for a double deep.


How exactly do you have a liquid phase if it sublimated?

Sublimation is the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage. For those of us interested in the water cycle, sublimation is most often used to describe the process of snow and ice changing into water vapor in the air without first melting into water.

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase. Sublimation is an endothermic phase transition that occurs at temperatures and pressures below a substance's triple point in its phase diagram.

Notice the above includes "Pressure" in order to achieve sublimation. So what is it? does OA sublimate which is what would be required to convert to Formic Acid or does it Vaporize in which case it remains Oxalic Acid? What you are describing would be vaporization.

Vaporization (or vaporisation) of an element or compound is a phase transition from the liquid phase to vapor There are two types of vaporization: evaporation and boiling.

Vaporization is what is desired while avoiding sublimation. I have yet to see anyone demonstrate that OA can be sublimated with these devices. I have yet to see anyone sublimate OA with any device.


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## aunt betty

There are some people with actual educations that think that sublimation and evaporation are synonyms. Good explanation but lets just let them keep using the term sublimation since it's been used in articles and documents that describe the OAV process. 
Arguing semantics with beekeepers gets old really fast.


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## JeronimoJC

Valid point! Most here only care about killing mites. If adding heat to OA causes the OA to sublimate or evaporate and this kills mites then great. If the OA process is deficient in killing mites, then by all means let's discuss the semantics.


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## viesest

> How exactly do you have a liquid phase if it sublimated?


We are not actually using OA but OA dihydrate.
From Wikipedia: "Typically, oxalic acid occurs as the dihydrate with the formula C2H2O4·2H2O"
Dihydrate liquefies and water evaporates, then pure OA is changing phase from solid to gaseous (sublimation). Soon after OA is again in solid phase (crystalline form).


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## crofter

viesest said:


> Dihydrate liquefies and water evaporates, then pure OA is changing phase from solid to gaseous (sublimation). Soon after OA is again in solid phase (crystalline form).



A very concise and correct description of the process we do when treating for mites with Oxalic Acid.
Some people are confusing themselves and others while trying to get their heads around it.


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## aunt betty

Just watched my OAV do it's thing and it's not sublimating. 

From the Varrox instructions:

2. MODE OF ACTION
" Oxalic acid is added to the pan, then the appliance ... As a result of the heating action of the pan, the oxalic acid *liquifies* and vaporises. Oxalic acid vapour fills the hive..." 

Apparently the English instructions are written in Great Britain English.

Now would be a good time to re-visit the concept of "latent heat". That explains why the solid does not completely turn to liquid before it vaporizes. Oh it liquifies just not all at once.


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## crofter

aunt betty; I thought you said beekeepers were not interested in things like "latent heat" and all those _semantic_ things Maybe when it thinks no one is watching your OAV sublimates!


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## challenger

I searched this thread figuring someone would have already asked this but not so far??
Anyway how can one treat with OAV if a top entrance is used? Is the vapor lighter or heavier than air?
Thanks


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## snl

challenger said:


> I searched this thread figuring someone would have already asked this but not so far??
> Anyway how can one treat with OAV if a top entrance is used? Is the vapor lighter or heavier than air?
> Thanks


Make a 2" shim/rim the same size as the hive body. Cut a slot in the shim for the Vap. Place the Vap on a 1/4" piece of plywood (4"x4") right on top of the frames. (The plywood is to keep the frames from scorching. Cover all with the inverted top cover. Connect the vap. 
As to the vapors. They will spread throughout the hive as a mist from a waterfall. The bees will fan it as well. 
Not hard at all.


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## erlaita

Hello
It is true that between 100ºC and 160ºC oxalic boils because it loses water of hydration. But between 160ºC and 200ºC (more or less) I have always seen that oxalic also continues to boiling in a certain way, and gradually disappears. I can not clarify to what extent sublimation or evaporation. Apparently, it seems evaporation. Maybe that happens because the temperature is not uniform in the pan, and the process is not simultaneous in all areas.


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## Daniel Y

erlaita said:


> Hello
> It is true that between 100ºC and 160ºC oxalic boils because it loses water of hydration. But between 160ºC and 200ºC (more or less) I have always seen that oxalic also continues to boiling in a certain way, and gradually disappears. I can not clarify to what extent sublimation or evaporation. Apparently, it seems evaporation. Maybe that happens because the temperature is not uniform in the pan, and *the process is not simultaneous in all areas.*


I added bold to the above quote. My comment. Exactly, a simultaneous process would be called an explosion. You don't see that with most materials.


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## Daniel Y

I will agree with the idea that what is boiling "Could" be other substances such as water boiling off. I have considered that and looked for informatin in regard to OA specifically. Does pure OA melt and boil or not. and have not come up with anything yet. Other than OA vaporizes at 315 degree but will sublimate at the higher temperature. so it is capable of doing both but requires a higher temperature for sublimation. sublimation is also what would convert it to Formic Acid. Coming full circle it would require the OA being at a higher pressure to even reach that higher temperature required for sublimation. And that is the best I have been able to gather information and that information is not of the highest calibur of reliability. Basically piecing together fragments here and fragments there. So both claims are true. vaporization of OA will produce crystals of OA while sublimation will produce Formic Acid. the question is is are we capable of sublimating OA and OA hot plate in a hive and I say no way unless you place that hive in a pressure chamber.

The idea that the OA vapor will get hotter simply becasue it is in a hot enough environment is nto true. OA cannot and will not take on any more heat unless it is placed under more pressure. all that other heat will do a lot of other things but it will not get the OA hotter. The OA cannot take on more heat. So OA starts out at room temperature. is exposed to a hot plate. IT increases in temperature to a certain temperature. at that point it can no longer take on more heat so it does something else with that energy. It melts. melting requires energy becasue it is work. After it melts it has to find something else to do so it vaporizes. Vaporization is converting to gas and this conversion also requires energy. So as the OA increases in temperature how it uses the energy of the heat changes. From warming to melting to vaoprizing. next it will combust.

Now if you put the oa in a pressure chamber you could get it hotter than that 315 degrees that normally it would have melted becasue Under pressure it can withstand more heat. get it hot enough by apply enough pressure and once again it will reach a temperature that it has taken all it can. it will then break down into other chemicals Formic Acid being one of those. a completely different use of he energy it has to do something with. Think of it as so much energy to expend it actually requires the molecules of OA being torn down and recombined. Btu you have to have leaped frogged over that melting temperature to get to energy level that high. and that would require higher pressure.

Keep in mind I am making a distinction between how hot OA while solid or OA as a liquid or OA as a gas can get. Since Sublimation is conversion directly from a solid to a gas. then of course we are discussion how you can get solidified OA past its melting temperature to it's sublimation temperature.


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## mathesonequip

sublination is going directly from a solid to vapor state, evaporation is going from a liquid to a vapor. to "evaporate" a solid, usualy the solid melts and evaporates. a liquid quickly evaporating we call boiling. slow sublination is called "freeze drying",,, unless your hobby is combining vocabulary and thermo-dynamics we are trying to split hairs here. i do not know what difference this makes??


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## crofter

Is it fact or fiction that oxalic acid breaks down to formic acid, carbon monoxide and water when it undergoes sublimation? If it is false we can forget about that whole idea!

According to the above post sublimation will only occur at a higher temperature than vaporization. Not talking about adding more heat energy; heat and temperature are not even close to being synonymous!

OA has been used as a catch all term but as viesnest pointed out the two forms of it monohydrate and dihydrate have very different properties. Some of the arguments here seem to take for granted they are identical. In the form beekeeps will see the OA Dihydrate first has to be converted to the monohydrate which is a solid from whence the sublimation occurs. We see this as melting into a liquid as the water boils off. If you apply energy too quickly it will boil over or splatter. As the water boils off the percentage of solids will increase and some vaporization or sublimation will start to occur. As has been mentioned these processes will overlap and occur together.

I think everyone is familiar with how a drop of water will dance around on a hot stove top supported by the layer of steam escaping from it. 

Now if you use drops of muddy water or containing dissolved solids you will see colored trails where the water droplet danced around. The water drop itself would not be above 212F, (its boiling point), but the temperature of the steam layer between it and the stove will be above this temperature otherwise no heat would be transferring into the droplet but we know it is getting smaller so have to assume a temperature differential. Note, the deposited mud or dissolved solids underneath the water ball or in its trail are quite free to rise to the temperature of the stove top. 

The oxalic acid monohydrate that is left behind as the water of hydration is driven off would be in contact with the pan of the vaporizer in a similar situation as the dissolved solid in the dancing water ball is it evaporates. 

What is the decomposition temperature? I think it is a fair bit higher than the vaporization or sublimation temperature and unless the pan is greatly over driven I doubt there would be more than a rather small percentage of the charge that experienced it. Somebody must have deemed it to be of some importance though as it used to be quite a precautionary advisory. Unless we ensure proper sizing of heat input by design or luck, we should not assume that portions of the pan are not at some higher temperatures than some of the contents and we also cannot assume that some solids cannot in that scenario, be overheating.

Incidentally many substances will sublimate from the solid to the vapor without going through the liquid stage and often at a much *lower* temperature than the melting point. Water is one such substance.


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## vdotmatrix

OMG


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## crofter

vdotmatrix said:


> OMG


Eyes glazing over yet?


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## Daniel Y

mathesonequip said:


> sublination is going directly from a solid to vapor state, evaporation is going from a liquid to a vapor. to "evaporate" a solid, usualy the solid melts and evaporates. a liquid quickly evaporating we call boiling. slow sublination is called "freeze drying",,, unless your hobby is combining vocabulary and thermo-dynamics we are trying to split hairs here. i do not know what difference this makes??


The difference is that the idea of converting OA to Formic Acid discourages some from using it. The discussion is to determine if it can even happen with this sort of equipment.


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## Daniel Y

crofter said:


> Is it fact or fiction that oxalic acid breaks down to formic acid, carbon monoxide and water when it undergoes sublimation? If it is false we can forget about that whole idea!
> 
> According to the above post sublimation will only occur at a higher temperature than vaporization. Not talking about adding more heat energy; heat and temperature are not even close to being synonymous!
> 
> OA has been used as a catch all term but as viesnest pointed out the two forms of it monohydrate and dihydrate have very different properties. Some of the arguments here seem to take for granted they are identical. In the form beekeeps will see the OA Dihydrate first has to be converted to the monohydrate which is a solid from whence the sublimation occurs. We see this as melting into a liquid as the water boils off. If you apply energy too quickly it will boil over or splatter. As the water boils off the percentage of solids will increase and some vaporization or sublimation will start to occur. As has been mentioned these processes will overlap and occur together.
> 
> I think everyone is familiar with how a drop of water will dance around on a hot stove top supported by the layer of steam escaping from it.
> 
> Now if you use drops of muddy water or containing dissolved solids you will see colored trails where the water droplet danced around. The water drop itself would not be above 212F, (its boiling point), but the temperature of the steam layer between it and the stove will be above this temperature otherwise no heat would be transferring into the droplet but we know it is getting smaller so have to assume a temperature differential. Note, the deposited mud or dissolved solids underneath the water ball or in its trail are quite free to rise to the temperature of the stove top.
> 
> The oxalic acid monohydrate that is left behind as the water of hydration is driven off would be in contact with the pan of the vaporizer in a similar situation as the dissolved solid in the dancing water ball is it evaporates.
> 
> What is the decomposition temperature? I think it is a fair bit higher than the vaporization or sublimation temperature and unless the pan is greatly over driven I doubt there would be more than a rather small percentage of the charge that experienced it. Somebody must have deemed it to be of some importance though as it used to be quite a precautionary advisory. Unless we ensure proper sizing of heat input by design or luck, we should not assume that portions of the pan are not at some higher temperatures than some of the contents and we also cannot assume that some solids cannot in that scenario, be overheating.
> 
> Incidentally many substances will sublimate from the solid to the vapor without going through the liquid stage and often at a much *lower* temperature than the melting point. Water is one such substance.


Steam is not greater than 212 degrees. I suppose I would have to look at ice and see if it can go directly from ice to steam. I also understand your point that if water or OA come into direct contact with a 1250 degree surface. it must be getting hotter than 212 degrees. not true. it reaches 212 and converts to steam. it just does so quickly. resulting in something more liken to an explosion rather than boiling. Would OA react the same? possibly, it might just result in a much faster vaporization. 

I did go look up several temperatures because it seems like quite a few are getting tossed around. Specifically the melting, boiling and flash point of OA. This is what I found. 
melting (sublimation/ vaporizes or boils) 216 to 217 degrees F dihydrate 214.7. (Note there is no boiling point listed for OA due to the sublimation. melting and boiling are basically the same temperature).
flash point is 331 degrees F. 
Sublimation (decomposes) temperature is 372 degrees F. 

So part of the issue is you have two sublimation temperatures. one where it sublimates to vapor while the other is a chemical decomposition. The vaporization happening just over the boiling point of water while the second happens well past the temperature that OA caught on fire. So as long as you don't catch your OA on fire I am not sure you have much to worry about.


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## Rader Sidetrack

Daniel Y said:


> Steam is not greater than 212 degrees


Steam under pressure certainly is greater than 212 degrees.

The temperature difference regarding the drop of water supported by steam on a hot surface is fairly small, but that steam _IS _under pressure. That small amount of steam is pressurized by the weight of the water droplet above the steam.

This is in reference to this part of Frank's earlier post ...


crofter said:


> I think everyone is familiar with how a drop of water will dance around on a hot stove top supported by the layer of steam escaping from it.
> 
> Now if you use drops of muddy water or containing dissolved solids you will see colored trails where the water droplet danced around. The water drop itself would not be above 212F, (its boiling point), but the temperature of the steam layer between it and the stove will be above this temperature otherwise no heat would be transferring into the droplet but we know it is getting smaller so have to assume a temperature differential.


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## Daniel Y

I suspect that the weight of water is already considered when it comes to the boiling point of water. maybe not. I would think that surface tension would also be a like factor. I know elevation changes atmospheric pressure and does effect the actual boiling point of water. Water will boil at a lower temperature here at 5000 feet than it does say in LA at near sea level. I don't think that indicates the steam gets any hotter. In fact by looking it up it does not. I looked up if you can burn water and so far came up with no you cannot. so the idea that water/steam ever increases above the 212 does not happen without an increase in pressure. Water placed directly on a burner not only transfers heat rapidly. possibly resulting in a violent or fast conversion to steam. but boiling itself is a metaphor for violent action. So it appearing violent is nothing new. Does OA react similarly? From what I can find OA does not boil. indicating it may not have a similar violent reaction. it simply converts from a solid to a gas. Consider the action of boiling to that of the steam rising from the pot. It would seem to me that OA may have the steam rising portion without the violent boiling portion. There is still the issue of other things in the OA and how they react. such as water. it will still act like water. How much would a fast heat transfer cause the water to erupt and disturb the OA?

I see three leading concerns with OAV.
1. does it even work?
2. even if it does work are you producing other nasties in the process?
3. it takes to much time, effort or both.

Faster treatment times seem to be getting hitched to issues of creating nasties. Seems to me an issue of seeing a ghost in all the places you cannot see.


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## crofter

Daniel much of the stuff you are expecting to be accepted as fact you are just pulling out of your hat. I know you like to argue! Where did you get that OA catches on fire? Where did you get that the sublimation temperature is 372F. 

The temperature of steam indeed can be increased far above its emanating temperature without the need to pressurize it further. You are confusing the elevated boiling point of pressurized water and subsequent steam temperature to indicate that steam could not ever be heated any hotter than the boiling point of the water that produced it. It most certainly can! Colloquially it used to be called dry steam ( steam at a temperature above its condensation temperature) Just add heat to it and it contains more energy at the same pressure. This is not advanced theory by any means.

Here is a link to some information on Oxalic acid and reactions. 

http://www.uq.edu.au/_School_Science_Lessons/UNChem1.html#3.30.10
3.30.10 Decomposition of oxalic acid
Oxalic acid begins to sublime at 100oC, becomes anhydrous at 189oC and when heated rapidly decomposes into carbon dioxide,
carbon monoxide, formic acid and water.

It seems oxalic acid will start to sublime slowly at even lower temperatures. The rate of heat input will affect the amount that sublimes and the amount that could be forced into decomposition. A gentle heat input will result in sublimation while rapid input will result in some decomposition. I would think this would be near the end of the process where the volume of the solid OA dihydrate decreases and the pan temperature increases. I think any reasonable amount of heat input would not cause decompositiion. 

What we as beekeepers are looking for is simply a change of state where oxalic acid is driven off in the form of a vapor which immediately reforms into the micro crystalline "smoke" that gets deposited on all hive contents.
It is not necessary or desirable to produce decomposition elements.


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## Daniel Y

Crofter, meet your own requirements and show your sources for information that you think you have about me.

This is one of my sources.

https://pubchem.ncbi.nlm.nih.gov/compound/oxalic_acid#section=Odor 
scroll down to 4.2.4 Also note that this list gives it sources.

as for your source
189 degrees C is 372 degrees F. So I guess you don't need my source for that information you found your own.
100 C is 212 degrees F. Which your source says is the temperature OA begins to Sublime. it does not give the range my source did and claims a lower temperature. Mine says 215.
It says nothing about how heat it to 372 degrees. Only that if you do and now evidently rapidly. Information in a search on how to Produce Formic acid from Oxalic acid is extremely contradictory to the claim that the heating is quick. one method requiring the heating of OA to a specific temperature range for an hour while additional doses of OA are added to a distillation chamber. A second method is described also requiring a distillation chamber the use of glycerol and OA mixture that then produces a rapid production of Formic Acid. but it is hardly done on a hot plate with OA alone.

Actually every method of obtaining Formic Acid from OA requires an OA glycerol mixture so the claim that you can convert OA to Formic acid is a half truth or otherwise known as a lie. Formic acid can be produced from a mixture. and OA is just one part of that mixture. Kind of convenient to omit that detail.


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## crofter

I see you are starting to get your head around the difference between sublimation and decomposition; good! I suppose the contradiction about temperatures required to achieve sublimation and avoid decomposition is the matter of degree. If your focus is to avoid the latter then slower application of heat is the takeaway. You are getting drawn off into the deliberate production of formic acid which is what is trying to be avoided here.

My source for steam theory goes back a lot of years to apprenticeship training. I just did a google now and if you want to get some steam theory search "dry steam, saturated steam" for starters. Lots of misconceptions about steam properties and in general change of state reactions of other gasses; Not much disagreement though amongst those who actually work with it.


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## mcifrani

Here is another version that another user had. Here is a small video and the diagram for wiring.





enjoy!


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## Rader Sidetrack

Regarding the formation of formic acid from (over)-heating of oxalic acid, this MSDS sheet for oxalic acid is interesting reading. 
http://hillbrothers.com/pdf/downloads/msds/sds/n/oxalic-acid-sds.pdf

Under the "General Fire Hazards" section of that MSDS is this little gem ...


> When involved in a fire, this material may decompose and produce irritating and toxic gasses (e.g. carbon dioxide, carbon monoxide and[HIGHLIGHT] formic acid[/HIGHLIGHT]).
> 
> http://hillbrothers.com/pdf/downloads/msds/sds/n/oxalic-acid-sds.pdf


That MSDS makes NO suggestion that the presence of glycerol is also required to produce formic acid from overheating oxalic acid. In fact, there is no mention of glycerol at all.



:gh:


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## mathesonequip

a couple of years ago back when oxalic acid vapor was an outlaw procedure in the usa, i talked to my son in law who has a phd. in chemical engineering, about oxalic and formic acids. only heat is required to change oxalic to formic as i recall. the acids act a lot alike and behave a lot alike and are very similar chemicaly. they have different melting and vaporization temperatures. super heating over vaporization temperature causes oxalic acid to change to formic plus more or less harmless by-products.


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## DRay

What temperature does it get? Does yours turn to liquid first or vaporize from crystals as suggested?


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## mathesonequip

DRay said:


> What temperature does it get? Does yours turn to liquid first or vaporize from crystals as suggested?


who cares about the exact temperature.. we are talking about working out in a field with a half dead battery and doing the procedure in a box full of bugs.. we are not doing this in a clean room labratory.. oxalic acid vapor works, do not get it instantly too hot. heating up a bit less than a teaspoon full in 3 to 5 minutes will do the trick.


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## aunt betty

mathesonequip said:


> who cares about the exact temperature.. we are talking about working out in a field with a half dead battery and doing the procedure in a box full of bugs.. we are not doing this in a clean room labratory.. oxalic acid vapor works, do not get it instantly too hot. heating up a bit less than a teaspoon full in 3 to 5 minutes will do the trick.


Yep and its fun watching the vapors coming out the cracks. Knowing the mites are in there going "oh no!" makes me smile.


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## pjigar

I was able to locate 10A thermostat disc on eBay for very cheap. 10 Pcs for $8! I am going to give it a try.
http://www.ebay.com/itm/391556627166?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Title: 10pcs Bimetal disc thermostat 160°C NC KSD301 right angle terminal Flush Mount


Thanks for the ideas. I am in Dallas, Texas area and have a milling machine. PM me if you need help.


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## pjigar

I was able to use 10A thermostatic disc in my design. I haven't tried treating any hive yet but "water boiling test" was a success!


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## Planner

Have you been to the emergency room yet?


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## johno

Just about completed my new vaporizer, just waiting on the thermocouple. So far costs from Amazon are as follows mypin temperature controller $24.00 Band heater 300w 110v $8.20 and type J thermocouple $7.00. 2" of 1" copper pipe, a 1" copper pipe cap, 8" of 1"by 1/8" aluminum bar, about 12" of 1/2" by 1/2" aluminum angle a few screws and pop rivets so a total of about $50.00. I also have a 800w inverter from Harbor Freight I bought for about $40.00 some years ago. So the temperature controller will allow the band heater to heat the copper chamber to 350 degrees and when that temp is reached after about 5 minutes the 3/8" pipe is placed into a hole at the back of the hive and a quarter teaspoon of OA is dumped into the chamber and is closed off, this will vaporize in about 30 secs I think as I have not timed it yet. I know the band heater heats it up fine but have not used it yet as I am waiting for the thermocouple.


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## mgstei1

Fantastic design like several European countries are producing. 
So the heating element, and controller are both 110 powered? 
I also like the idea of just a 3/8" hole for the OAV to enter the hive. 
That unit is a guaranteed home run. So you will use 2 caps when vaporizing right? 1 to have filled and placed on the cup, turn it upside down to vaporize and then fill the 2nd with OA and when the 1st one is complete turn it back upside down and remove it and place the newly charged cup on and then flip it?
Be nice if you can use a silicone,teflon or HDPE cap that can withstand the 350degf and not have to burn a finger

I want to purchase your 1st manufactured unit here in the states when you start producing them.


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## johno

We still have to try the system out mgstei1, I have had my days in manufacturing and as I am rapidly approaching 73 I will not be starting again, however I am quite willing to help other beekeepers build their own. 
Johno


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## pjigar

pjigar said:


> I was able to use 10A thermostatic disc in my design. I haven't tried treating any hive yet but "water boiling test" was a success!
> 
> View attachment 28282
> View attachment 28283
> View attachment 28284


My vaporization time with 160C thermal switch is 5 minutes. I am always left with some crusted and un-eveaporated oxalic acid in the tray so I am going to try bumming up the temperature to 165C.


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## johno

The system that I am working on will preheat the pan to 350 degrees so that when the OA is added it should vaporize in about 30 seconds, also the 3/8" nozzle is inserted into the hive so no hot pan is in the hive and no bees or queen can get fried.
Johno


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## razoo

johno said:


> The system that I am working on will preheat the pan to 350 degrees so that when the OA is added it should vaporize in about 30 seconds, also the 3/8" nozzle is inserted into the hive so no hot pan is in the hive and no bees or queen can get fried.
> Johno


Johno, 

I am interested in your system. Can you post more details?


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## Daniel Y

I would be interested in seeing any figures of what temperature a plate needs to be to get OA to vaporize. as an example a 350 degree plate will not necessarily heat oa or anything else on it to 350 degrees. A more actual example is a propane torch heating copper pipe. The flame of the torch is over 3600 degrees. The melting temperature of solder is 360 degrees. anyone that has sweat a pipe knows that a propane torch does not get copper pipe to the melting temp of all that fast. So where is all that heat going. this is due to issues with thing like efficiency and heat transfer. some things resist taking het while others take it readily. and the heat will go where it is easiest to go. to the moisture in the air is one of them. the same will be true whether it is a metal plate or a flame. this example shows that in at least one case to get something to 360 degrees (copper pipe) it takes a while for even a 3600 degree heat source to get it there. there is nothing quick about it and to raise the temperature to above that would take an additional considerable amount of time.


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## johno

Hi Daniel, it all depends on the efficiency of the system that will decide the amount of calories it will require to raise the temperature to any given temperature. All I can say is that the oxalic acid is dropped into a container that can be controlled to any set temp so the OA will sublimate rather quickly. Now what I want to see is to what temp the system will get to if not controlled, as the one I tested was not controlled and worked very well. From switch on to when ready took four and a half minutes.
Johno


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## johno

I have posted some details and pics under VM vaporizer on the commercial postings.
Johno


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## johno

I have now fitted a type K thermocouple to my new vaporizer and find it heats up to 350degrees in 4 minutes. Tried to check the accuracy of the read out by boiling water in the vaporizer and found it boiling at about 184 so I need to adjust by about 20 degrees if I can figure this mypin language out. I treated 14 hives at home this morning using 2 of these vaporizers allowing 5 minutes for them to heat up and then vaporizing for 1 minute per hive hoping to really cut back on time. So the total time to do the 14 ended up at 22 minutes not much time saved if I had used only one vaporizer. I think you lose more time going from hive to hive with 2 vaporizers than you would with only one. I will give them another shot in December and use only one and see how that time works out.
Johno


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## Artur_M

Too many opinions about temperature of vaporization.

Did anyone tried to make it using wood burner? I read it goes up to 950F.


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## Jim Hancock

For what it's worth - Champion 198 glow plug 140 watt 11v, shown as a replacement for Autolite 1104 127watt, at Rockauto.com for $3.61 plus about $2 shipping. I'm ordering 2 for $9.75 with shipping. 5% discount code 5607427050042966 enter in "how did you hear about us box."


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## pjfam

About that heat transfer. I have that paste one uses between a motherboard and it's heat sink. If I pack that in the glow plug hole will I get better transfer


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## deenr

I've been through two autolite glow plugs today. I put my ampmeter on to monitor and an infrared thermometer as well. All looks good to start (14.5 amps and temp starts to climb but at 49 and 74 seconds the current flow stops. I pulled the glow plug and found they had ruptured both times. I drilled and tapped (10mm 1.25) the block to assure good continuity. I'm new here but ill try to attach a pic.


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## Jim Hancock

I took the nut off mine and drilled a tight hole. I then cross drilled and use a set screw to hold the glow plug in and help with heat transfer.


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## deenr

I must have the wrong glow plug. The model i bought just had a smooth shaft on the connecting end. Luckily the size matched a standard but spice connector. I'm reading on a diesel forum that autolight plugs are notorious for swelling and failing. Guess ill try to find another brand tomorrow. Oreillys only stocks autolite


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## pjigar

Be sure to have tight tolerances where glow plug element makes contact with the aluminum block. I also used some heatsink compound in the assembly to get optimal heat transfer. I also have temperature control switch is series to make sure I don't overheat the glow plug. Typical car will only pump current for 10s of seconds max but we need to maintain temperature for 3-5 minutes so the temperature switch is essential.


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## Jim Hancock

The heating element is tapered. If you remove both nuts on the threaded shaft end you can push the heater out of the large mounting nut. Be careful not to short the connection when you connect the wires.


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## deenr

Found the problem. When all else fails, research lol. I asked the dude at oreilly of all glow plugs were 12v and he said yes. Turns out 1108 he sold me is a 6 volt plug. Going to NAPA this morning to grab a 12v 175W champion. Thanks for the replays.


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## Brianshoney

Hello BeeAttitudes,

It's been a few years and beekeepers are still finding this post when they Google long enough. This appears to be one of the most relevant threads on this topic. Where did you source the thermo disk? And are you still using this design?


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## pjigar

Update: Do not use solder with any terminals on this vaporizer. The soldered joints will melt due to high temperature and current flowing through them. Instead, shrimp the connections.


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## Andhors

Of course it’s better to buy the premade equipment. Some of us need to learn the hard way!


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## sk8er72

My 12 volt battery is dead, I had need to use my oxalic acid vap, I tried a golf cart 8 volt and it did not get hot enough. If I but two, 8 volt together to make 16 volts will that destroy my vaporizer. I have a Kelly beekeeping OA vap. 
any thoughts
Thanks
John B


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## crofter

Many of the designs use automotive diesel glow plugs as the heater. Some I have used are only rated for 11 volts continuous and this is with the body screwed into a solid heat sink. They are on the ragged edge at 12 volts so I sure would not recommend them across two 8V batteries in series. Hooking in parallel will not increase the temperature.


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## adammccoy

Not sure if this is the best place to post this, but I have a modification to a cheap vaporizer I bought off of ebay that others might like to use. My Lang hives have screened bottoms so they need to be closed for OA treatment anyway. 
My modification is I used high temp RTV to attach the bottom of the vaporizer to a piece of cementboard siding that I had leftover from a chicken coop project and also attached the metal/foam insert that closes the entrance to the siding. Note: this is cement siding, so only about 1/4 inch thick or less not cementboard backing which is thicker. 
I cut the siding to fit the inside dimension of the bottom board except it closes the entrance when about 1/4 inch from the back wall (it is sitting on top of the wooden lip at that point). 
It isn't air tight but seems to close the hive up pretty well without needing rags or the like. The cement board doesn't burn. You have to slide it in slowly so the girls can get out of the way, but otherwise pretty simple to use. 
Hope someone else can use this idea.

To be clear, the cement board goes in the entrance and sits above the screen. It does not slide into the slot for a sticky board.


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