# OAV crack pipe method



## rookie2531 (Jul 28, 2014)

I have read a little about OAV and it seems that everyone that does it is OK with it, but only if you use the commercial vaporizer, If you put it in a pipe and torch it, then people seem to think that is bad, heard it called crack for bees. Well I'm trying it in the pipe first, before investing in the vaporizer, to see if they make it through the winter. I do think my first attempt was somewhat of a failure. I used 1/2 teaspoon on a deep and 2 medium hive. I used a shim on top and plexiglass so I could see what was going on. It smoked for a few seconds and was done. I think I burned it too quick. Do you think that putting a candle under the pipe would get it hot enough to smoke, even if it took longer?


----------



## SallyD (Mar 12, 2011)

There is a youtube video on this- the guy used a blow torch not a candle. What happened the first time you used it? Did you lose your bees? I was thinking of doing the same thing but I am not too handy with tools. Can you share how you make yours (you can PM me if you want). Thank you!


----------



## rookie2531 (Jul 28, 2014)

I didn't seem to lose them, yet when the 1/2 teaspoon burned up quickly, it did cover the bees that were on top in white crystals. And it did seem to bother them. I let them out after 2-3 minutes and didn't keep them cooped up for the ten recommended. I have seen the video where the guy does it, but no bees were present and it seemed to smoke for a long time. I just used a piece of pipe that was straight and I used a hammer to pinch the one end shut and then folded over and hammered it down again. I think I will go and buy some hardware and make a vertical piece, that may help burn it slower.


----------



## WWW (Feb 6, 2011)

The straight pipe will work just fine however you must use a slightly larger hole in the shim to allow the tail end of the pipe to drop down lower than the end that is in the shim or when the OA becomes liquid it will pour into the hive leaving you with very little left to evaporate.

I also used a pipe as a trial before buying a Heilyser unit, I needed to know that it worked before spending the money and it does work wonderfully as a cheap way to kill mites.

Edited to add; I seriously doubt that a candle will ever get OA hot enough to vaporize.


----------



## mgolden (Oct 26, 2011)

Went to a larger home hardware store and picked some brass garden hose ends and had aome 1/2 copper tubing on the shelf at home . Used 9 inches of pipe. Has a 1 inch brass screw on cap - works well for refilling. You will need to do a little soldering as well.

If you fairly slowly heat the base where the acid is and also run the torch up and down the tube, it works pretty good. Need to slowly heat the acid to prevent it from turning to formic and ?CO2. Also need to keep the heating the tube as the vapor condenses to the inside and will block the vapor flow.

I never timed the heating process but took maybe 5 minutes. There was a white film covering tops of frame. 
I didn't like that the vapor enters the top of the hive and may not be getting throughout the hive as good as it should. Applied it 3 times, a week a part. Didn't seem to harm the bees at all. I don't know how oxalic acid works on the mites to kill them, and haven't been able to determine that so am not confident. 

It's been cool weather here and I haven't got to a mite count. I will also be making up a mite drop board - recently learned how simple they are to make and insert in a bottom entrance with solid bottom board. Going to make a plastic sheet, cover it with a mesh, cover with something sticky(cooking oil or vaseline). Then cover with 1/8 screening and will do a further test.

So I just tried(yesterday) a heat gun with a rolled up piece of aluminum sheeting. There was a recent thread(last ten days) and a pic in it. Have a 90 degree curve to my copper tubing. There was a recent thread(last ten days) and a pic in it. 

Also drilled a 3/16 hole in cap, so you get hot air blowing through the tube to prevent the crystalizing. Seemed to need 410C setting on heat gun to vaporize. 

Looks very promising. The OAV 12 V probe vaporizer is $155 here.

It's Canadian Thanksgiving this weekend, so we will be away this weekend and will not get back to my OAV pipe crack project and trial run on an actual hive for a week or so.


----------



## Michael Bush (Aug 2, 2002)

The main downside to the pipe method is you have to really pay attention to the wind or you may inhale the vapor. If you do inhale it you will know why you should avoid it... it is very caustic and dangerous. You need to at least have a smoker lit so you can see the drift and got to whatever lengths to be upwind. With the tray you still need to be upwind, but you can be 20' or 20 yards up wind... depending on the length of the leads...


----------



## WWW (Feb 6, 2011)

Yes I definitely concur with you Michael, one must be extra extra careful when using the pipe method since it places you right up next to where the OA is being vaporized. I might also add that using a hot air blower will put positive pressure inside the hive and the OAV will come billowing out any crack or hole that is in the hive so do be careful when experimenting with these devises .


----------



## SallyD (Mar 12, 2011)

Michael Bush said:


> The main downside to the pipe method is you have to really pay attention to the wind or you may inhale the vapor. If you do inhale it you will know why you should avoid it... it is very caustic and dangerous. You need to at least have a smoker lit so you can see the drift and got to whatever lengths to be upwind. With the tray you still need to be upwind, but you can be 20' or 20 yards up wind... depending on the length of the leads...


That is what scares me about making my own. Who sells these?


----------



## snl (Nov 20, 2009)

SallyD said:


> T. Who sells these?


Go to OxaVap.com to get more info, see one in action and purchase!


----------



## sqkcrk (Dec 10, 2005)

rookie2531 said:


> Do you think that putting a candle under the pipe would get it hot enough to smoke, even if it took longer?


Do you mean a Bong? Maybe a Bong would work better, but I don't see how you are going to get bees to toke on it, their mouths being so small.


----------



## Harley Craig (Sep 18, 2012)

mgolden said:


> If you fairly slowly heat the base where the acid is and also run the torch up and down the tube, it works pretty good. Need to slowly heat the acid to prevent it from turning to formic and ?CO2. .


where do people come up with this crap? it's simple science. In an open vessel pan or tube you simply cannot heat something past it's boiling point because it vaporizes off. The only way to heat it hot enough to turn to formic would be in a closed vessel and then guess what.....you don't get any vapor because you are pressure cooking it. That is why we pressure cook food, to increase the temp to kill bacteria that wont die at 212 deg


Edit: Mgolden I'm not directing this directly at you, I have seen this same theory mentioned several times here and people keep repeating it.


----------



## crofter (May 5, 2011)

If you first heat the pipe at the discharge end before heating the OA end you will not have the vapor solidifying at the exit. The problem with solidification there is that you don't know how much of the measured dose actually got delivered to the bees. It actually would be difficult to get dissociation conditions with the pipe system and impossible with any reasonable tray type evaporator.

It has been repeated a number of times here on the forum that an unpressurized vapor cannot be heated to a temperature higher than the boiling point of the liquid it came from. That is simply not correct: it is probably a misunderstanding of what is a fact, that the* liquid* cannot be heated above boiling temperature unless pressurized. The link below is to one explanation if you want to get this straight. This is standard physics theory not a matter of opinion.

http://books.google.ca/books?id=GiY...a=X&ei=jiU4VJmdI-_msATf3oLYBQ&ved=0CEwQ6AEwBg


----------



## dsegrest (May 15, 2014)

The vaporizer costs about the same as 1 nuc. It doesn't kill the hive. This doesn't take great actuarial skills to see that using a real vaporizer is better than taking a chance with something that might work. 

Anyone too cheap to buy a vaporizer should use dribble. It seems pretty complicated to me but it does seem to be safe for the bees.


----------



## sqkcrk (Dec 10, 2005)

Is this method really a good idea? Is it at all safe? Plenty of people try to do something on the cheap oinly to pay for it later and often costing much more, and much more than money.

"Be safe out there people."


----------



## crofter (May 5, 2011)

The pipe method is cheap, quick and dirty! You will get whiffs of the vapor that way. If you decide to do it, a helpful temperature indicator is a piece of poly flexpipe material to rub on the heated portion. The right temperature is about where the plastic just starts to grab and smear onto the heated metal.


----------



## Harley Craig (Sep 18, 2012)

crofter said:


> If you first heat the pipe at the discharge end before heating the OA end you will not have the vapor solidifying at the exit. The problem with solidification there is that you don't know how much of the measured dose actually got delivered to the bees. It actually would be difficult to get dissociation conditions with the pipe system and impossible with any reasonable tray type evaporator.
> 
> It has been repeated a number of times here on the forum that an unpressurized vapor cannot be heated to a temperature higher than the boiling point of the liquid it came from. That is simply not correct: it is probably a misunderstanding of what is a fact, that the* liquid* cannot be heated above boiling temperature unless pressurized. The link below is to one explanation if you want to get this straight. This is standard physics theory not a matter of opinion.
> 
> http://books.google.ca/books?id=GiY...a=X&ei=jiU4VJmdI-_msATf3oLYBQ&ved=0CEwQ6AEwBg



the crystals turn to liquid long before the boiling point and your link doesn't work. If you were hitting the crystals directly with 3623 deg F I could see how some could convert but transferring that heat through copper no way, it will turn liquid before boiling thus not exceeding it's boling point.

Edit: the link started working but it talks about super heated vapors in insulated pipe which is NOT an open vessel. Yet a homemade OAV applicator has a pipe but the length isn't going to be enough to restrict enough to superheat the vapor


----------



## Harley Craig (Sep 18, 2012)

sqkcrk said:


> Is this method really a good idea? Is it at all safe? Plenty of people try to do something on the cheap oinly to pay for it later and often costing much more, and much more than money.
> 
> "Be safe out there people."



of course it safe if you wear the proper PPE which I would highly recommend no matter what method of delivery.


----------



## sqkcrk (Dec 10, 2005)

Is there a Youtube video of this? All I can imagine is a long tube w/ something burning at one end and someone's mouth at the other. Show me what is being discussed here, please. I am not familiar w/ this method of applying OA.


----------



## Harley Craig (Sep 18, 2012)

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


----------



## crofter (May 5, 2011)

Take that out of your mouth Mark, you dont blow on it to make it work! Yes I am sure there are lots of vids. on YT and a few on Beesource too.


----------



## Harley Craig (Sep 18, 2012)

I think most people do it closer to this way. The one hive I've treated this way , this is the type that I used. The length of pipe is less than 3 inches so not enough to build up pressure to get the liquid to overheat.

https://www.youtube.com/watch?v=RB7xaF7sVIY


----------



## crofter (May 5, 2011)

You dont have to worry at all about overheating the liquid;that is not the concern. You also would not have to build any pressure in order to heat the vapor beyond its issue temperature. I dont think it would be likely at all to occur unless you used a longish discharge pipe and overheated that section. Since a vapor has very little mass, radiant heat can raise its temperature in a flash.

I think for the most part the dissociation of OA is more a bogeyman than a probability. In the worst case scenario with the home made pipes only a small portion of the charge might break down. The breakdown products are formic acid vapor, carbon monoxide and water vapor. What would happen then is that the portion of the charge that dissociated would not contribute to the fine deposit of oxalic acid micro crystals inside the hive. This deposit from what I gather is the key to its effectiveness. 

You need to put some heat into the whole length of the pipe or you will have the issue of re solidifying at the discharge end. This has been mentioned by quite a few posters. Again this portion of the charge would effectively not reach its target inside the hive. I think as MGolden suggested even and gradual heating of the pipe would be the way to go.

When you have to get down in front of the hive and carefully heat the pipe a full fitting cartridge respirator should be considered a must.


----------



## Ray4852 (May 27, 2011)

Its cheaper to buy a vaporizer. 165 dollars for vaporizer, 15 dollars for 5lbs of oxalic acid is pretty darn cheap way to treat for mites. Look what it cost to buy a 5 frame nuc. One year a vaporizer will pay for itself. Safety first with oxalic acid. Its take a few with no common sense to give this product a bad name.


----------



## mgolden (Oct 26, 2011)

The crap about formic acid and CO came from this forum and Scientific Beekeeping. See Section 2 of Oxalic Vaporizing about three quarters way through.

If it all turns to liquid and then evaporates then maybe no problems. On occasion there is some residue in heat chamber, and can this get overheated. 

When using the hot air gun, the copper tubing is bent to be 90 degrees to air flow and hot air is not blown into the hive. 

The vapor is supposedly quite damaging to mucous membranes so get upwind or use PPE.


----------



## Colino (May 28, 2013)

SallyD said:


> That is what scares me about making my own. Who sells these?


I bought this one for $100 including shipping. You have to add your own leads which cost me about 5 bucks. I used it yesterday for the first time. Make sure you suit up if you use it, the girls were pissy after to say the least. I looked this morning and there are drifts of dead Varroa against the entrance reducer. I think I waited too long to do this, I'll remove my sticky boards tomorrow evening and try to get a picture, it's not a pretty sight.
Colino
http://www.members.shaw.ca/orioleln/vaporizer.html


----------



## rookie2531 (Jul 28, 2014)

I think I figured it out. I went to hardware store and bought brass pipe and fittings. Practiced a couple times and seems to work better (smoke longer) when I focused the heat more at the exit side and worked the heat down to the acid. I also kept the torch moving more quickly and would alternate a full pass for the whole pipe then two passes on the top pipe and one on the bottom. Then 3-2 passes and back to one full pass.


----------



## crofter (May 5, 2011)

Rookie 2531; sounds like a good description of even heating. The mites won't like it all!:thumbsup:


----------

