# Commercial OAV... not working?



## Woodside (Aug 10, 2010)

I seem to be having some poor luck with OAV. I recently bought a commercial OAV piece of equipment. The general principal of the device is blowing complressed air over a pocket of liquid boiling oxalic acid crystals. I usally put a mounding tablespoon of acid in and vaporize around 6 hives with that amount. I stick the nozzle into the entrance and blow in the white fog for about 8 seconds on a double deep. The vaporized acid fumes out of the top of the hive between the cover and hive if not perfectly sealed. I am not exactly sure on the total amount of grams I am using but figure its close to 2 grams per hive. Anyway... I have treated every hive four times... Once a week for 3 weeks. Then once more last week, which was about 3 weeks after the initial treatment. I went out today to dig in hives and do a few ether rolls. To my disappointment I had over 10% infest rate. This is absolutely unacceptable and I am hitting them with a real treatment this week.

I am not sure if for some reason this faster paced method somehow isnt working or maybe OAV in general doesnt work as well as everyone seems to claim. any suggestions?


----------



## Billboard (Dec 28, 2014)

Im using a vaporizer and letting the fumes come out the top cover, like you. My first 24 hr drop count is in the hundreds, it works. And less everyday after that.


----------



## snl (Nov 20, 2009)

Woodside said:


> I am not sure if for some reason this faster paced method somehow isnt working or maybe OAV in general doesnt work as well as everyone seems to claim. any suggestions?


OAV certainly works as well as everyone claims, over 20 years of use in Europe proves that. OA really needs to stay in a closed hive for 10 minutes. I'm guessing you're not closing off your hive afterwards and the vaps are escaping way too soon. I know closing them off can be a pain for a commercial operation, but how about throwing some wet old sheets / old beach towels over them to hold in the vapors for time needed...


----------



## JRG13 (May 11, 2012)

Could be a dosage issue. I would dump in two grams, see how long it takes to burn off, then do it again with 4 grams, time it again. Get an idea of grams per time unit that is getting burned off and adjust the treatment that way. My personal theory is that timing is everything with OAV, and if you have active brood cycles going on, with bad luck, you just happen to miss mites emerging and being able to get back into capped brood before the next treatment.


----------



## snl (Nov 20, 2009)

JRG13 said:


> My personal theory is that timing is everything with OAV, and if you have active brood cycles going on, with bad luck, you just happen to miss mites emerging and being able to get back into capped brood before the next treatment.


Mites stay phoretic 7-14 days after emerging..... they don't just hop back into brood...


----------



## A'sPOPPY (Oct 13, 2010)

Is weekly OAV being promoted, if so by whom?


----------



## snl (Nov 20, 2009)

A'sPOPPY said:


> Is weekly OAV being promoted, if so by whom?


No, not a weekly treatment as an going treatment. However, at this time of year the mites are out-breeding the bees, so a treatment regimen every 5-7 days for 3 weeks will kill GT 95 % of the phoretic mites on the bees during the first treatment and again another 95% of the mites in succeeding treatments as they emerge with the brood and are in their phoretic stage. OxaVap has sold OA vaporizers for the last 3 years and worked with the EPA during the legalization process. We have also researched many of the studies on OAV. There are many, many posts here on BS regarding OAV. A few searches will yield you a long night of reading.


----------



## Oldtimer (Jul 4, 2010)

Woodside what vaporiser are you using, the Lega one?

If so it's the same as mine, I find that because it holds a bulk amount of OA, and OA has a water content, when I first turn it on a lot of the vapour is actually steam. I have to let this boil off and can test when a good amount of OA is coming out by pointing the nozzle at a hive body and seeing if a good crystalate forms on the box. If so, it's ready to use and I start dosing hives.

Also, unlike the small one shot heat only vaporisers, my vaporiser blows a lot of air in also, presumably what goes in must come out so I assume I loose some of the OAV, so I dose at a higher rate than recommended. I've experimentally dosed more than double recommended which seems to have no detrimental effect on the bees at all, as it's a vapour not a dribble mixed with sugar.


----------



## Chip Euliss (Sep 2, 2010)

Oldtimer, what temperature do you set the heat gun on the Lega vaporizer? Looking into getting one if we get state approval here in North Dakota. I looked at some of the Lega literature and they say you can do 60+ hives per hour. Based on your experience, is that a reasonable number? Thanks in advance! Chip


----------



## Oldtimer (Jul 4, 2010)

I wind the temperature right up, there is a lot of air blowing through and if you keep it down at recommended temperature you don't get a really good cloud of vapour coming out. Turns out the OA changing into formic acid is not a great issue in normal air pressure conditions.

Yes 60 hives an hour is about right long as your set up procedures are organised properly.

Here's a link to a video of me doing it, the video has been linked on Beesource before so don't bother if you've already seen it. It may not play properly on explorer but should on a different browser like Chrome.


----------



## Chip Euliss (Sep 2, 2010)

Thank you very much--looks like a great system! Looks like you have a different heat gun than the one Lega provides with their vaporizer. Is it a replacement or one you bought to run on 120 vs 220?


----------



## Oldtimer (Jul 4, 2010)

It's a 220 V one which is our standard over here. I got the Lega supplied one also which is fine but bought a spare gun in a local hardware shop just incase one failed during use.

Someone did mention that the 110 V guns don't put out the same heat but that was just hearsay, where you are you'll be wanting a 110 V gun so would just pay to check temperature output on it before buying. My one can run at a theoretical maximum of 630 C, what I do is start it at that, but after a few hives it gets obvious the whole thing is getting pretty hot I'll wind the temperature back to 400 or so. Not sure how accurately the temp on the gauge reflects what is actually happening in the chamber that holds the OA, I think it may be lower.


----------



## Woodside (Aug 10, 2010)

thanks for all of the input. I think I will treat each hive for 3x to 5x longer and check results. I feel like my setup should be working great however I must just be getting too low of a dosage with all variables considered.


----------



## Chip Euliss (Sep 2, 2010)

Very informative thread--Thanks Woodside!


----------



## Robbin (May 26, 2013)

I don't use a heat gun, but as far as being effective, I get 2nd day drops following the first treatment in the thousands... It is very effective. One thing I've noticed is the first "smoke" coming off my unit is probably all steam, then
a second round of smoking begins, and I think that is the actual acid vaporizing. Not sure how you would account for that if you are loading up for more than one hive at a time. I would suggest you do a test case of six hives
and see how each one responds. It is possible that hives early in the process are getting more steam and less OAV then hives later in the process.


----------



## HeritageHoney (Feb 28, 2013)

Woodside,
If your referring to the stainless steel commercial one that is available, I'm familiar with it through another beekeeper who has started using it. He couldn't get much support from the guys who make it and sell it, but he ended up getting some good real-world advice from another comm. guy who has been using it for several years with good results. 
From you post, and from what you just stated above, you need to go longer at each hive. Rather than 8 seconds, go for 20-30 secs each hive. This time frame has been working good for others. Also, pay attention to the thickness of the vapors coming out of the device. It's totally subjective, but you have to watch for the steady, consistent stream of vapors verses the inconsistent flow. I think as more guys with mechanical minds start playing with this now that it's been approved, we're going to see some leaps in design improvements that will help in many areas. Some have stated that they doubt this b/c of how long it's been used in Canada and Europe, but I already know some pretty smart guys working on it (plus a few ******** who can come up with some pretty sweet stuff.


----------



## snl (Nov 20, 2009)

I'm thinking that w/o a dose per hive measurement, how do you know how much each hive is receiving? Also, with temps fluctuating... Again, how much OA is actually entering each hive?
Sorry, don't have any answers, just questions.


----------



## Oldtimer (Jul 4, 2010)

The dose rate for these pressurised air systems is a problem, with current technology anyway, it's just not possible to measure exactly.

But for me, I just err on the side of overdosing, doesn't seem to do any harm.


----------



## beepro (Dec 31, 2012)

HeritageHoney said:


> I think as more guys with mechanical minds start playing with this....see some leaps in design improvements that will help in many areas. Some have stated that they doubt this b/c of how long it's been used in Canada and Europe, but I already know some pretty smart guys working on it (plus a few ******** who can come up with some pretty sweet stuff.


Waiting for Barry's approval to release it here!

Sweet it is! Been plagued by the mite foul broods for 2 seasons now which hinder my hives to expand both in the Spring and Fall build up.
All of my hives should expand significantly now that my new invention, a stationary oav gadget using your everyday household materials that I had tested extensively before putting it to use under my hive. It uses an external heat source that is insulated so does not cause any fire or burn the hive up. After the V1 (first version) success I'm
on my V2 now with its expanded coverage area to treat the hive. All timing is 2 minutes or so depending on the amount of oa put in. See the V1 link at 
https://www.youtube.com/watch?v=4D2vLtiF2fI
And speaking about the amount of oa to use, during my testing trials with many coughs because I did not ware a gas mask but bought one, come up with some really interesting facts.
Will let you see my trial test vid on the oa burning in my V1 gadget once approved. This was to size the amount of oa to put in my gadget. 
So to answer the how much to put in question. It depends on the amount of oa put in the pan and the timing of it. From my open air oa burning trials, first the
excess moisture will be burn off and then the oav will come out. This depends on the season too. In the summer time it is dryer than the Fall and winter time. Because
the oa absorb moisture in the Fall you have to give it a longer time assuming that the dosage is the same every time. I try to put in the same amount and leave it
in 30 seconds longer than the 2 minutes allowed. My observation on the oa burning is much like that of OT's. How the V3 and V4 will be improved? This depends on how
creative is our member's inventive minds once released here.
Maybe the OP should put it in longer because it is the Fall now?


----------



## Oldtimer (Jul 4, 2010)

Beepro I tried to watch it but was requested to sign in to confirm my age as the content may be inappropriate. 

Anything you can do to fix that? I don't sign in to you tube.


----------



## beepro (Dec 31, 2012)

Sorry, OT!

This is for the minor's protection as we have some members here who are kids also.
Kids will break all rules these days. For the adults I am not that concern. Dealing with the oa
kids should be off limit. I'm very careful with my invention to get in the wrong hands.
Perhaps someone nearby can login to youtube for you to see the vid.


----------



## Oldtimer (Jul 4, 2010)

OK well although Youtube will not let me play the video unless I sign in, weirdly enough, I was able to download it without signing in and have watched the file on my computer.

Certainly looks like your gadget makes plenty of vapour Beepro, pity you did not show the actual gadget. I didn't see anything that would be scary to children.


----------



## BeeBop (Apr 23, 2015)

Looks like it was just getting going good at the 2 minute mark. How long did it take to finish?

And what's the "mystery device"? I just saw vapors coming out of a hole.


----------



## beepro (Dec 31, 2012)

At about 590° to 680° C (about 1090° to 1250° F) operating temperature, this gadget is designed for a quick 2 minutes burn time. After many test trials I found this is the best burn time to get the most oav out and not overdose the bees and damage the gadget. So it is a quick time and high intensity gadget.

OT, V1 vid is not the scary part but the how to part on V2 that is the most frighten to the little kids here. I have not upload those yet. Then we have the enhanced gadget for more vapor delivered into the hive both on the V1 and V2. The V1 after it got improved is really powerful now. Got a vid of it (v1) in action too. Poor little bees all got turn into little white bee ghosts after the treatment. Cannot say much about the mites. Will check on that tomorrow morning.

BB, at 20 seconds it starts to vaporize but not much. At 1 minute things start to get cooking. At 1 minute and 40 seconds things are really interesting though the structural integrity of the gadget is still holding strong. And from 2 minutes to 2:20 things are tapering off including the vapor. So you see, without overdosing the hive on oa, this gadget is designed to burn for max 2 minutes only without putting the structural integrity at risk including damaging the gadget and burning up the hive. See 2 posts on here in a week already.
Everything has its principles and secrets if you know how to find it. Now is the time to further fine tweaked this invention. Commercial application is quite possible with more improvements and the right materials used and its design.


----------



## Rader Sidetrack (Nov 30, 2011)

beepro said:


> At about 590° to 680° C (about 1090° to 1250° F) operating temperature, this gadget is designed for a quick 2 minutes burn time.


Interesting temperature range. 

Note that according to the CDC, oxalic acid Sublimation temperature is 157° C (314.6°F) and the "Melting point ([HIGHLIGHT]decomposes[/HIGHLIGHT]) of oxalic acid is 189.5°C (373°F). 

Randy Oliver has some interesting comments about oxalic acid at high temperatures ...


> How does oxalic vaporization work? In the CRC Handbook of Chemistry and Physics we find that upon heating oxalic acid, the water of hydration boils off first, then at 315°F the oxalic acid starts to sublime (go directly from solid to vapor), and finally at 372°F any oxalic acid which has not yet sublimed decomposes to formic acid and carbon monoxide. The hot vapor rises within the confines of the hive bodies, and recondenses into tiny crystals that coat everything inside the hive. [HIGHLIGHT]One of the problems with some vaporizers is that they get too hot too quickly and decompose, rather than evaporate the acid.[/HIGHLIGHT]
> 
> http://scientificbeekeeping.com/oxalic-acid-heat-vaporization-and-other-methods-part-2-of-2-parts/


Just for a comparison, aluminum melts at 660.32 °C ​(1220°F).


----------



## beepro (Dec 31, 2012)

dups!


----------



## beepro (Dec 31, 2012)

Rader, you got a good point. What makes this works is the reduced in temperature even though the range 
specified is what a pure burn form will have. There are 2 natural build in layers of temperature reducer that enable my stationary oav gadget
to work. The higher the temp. went the more temp. got reduced until it reached an equilibrium state for the oav to come out. Oh, cannot wait any longer for Barry's response to release all the good details. At the high temp. that you and randy mention, all the oa put in will not work. Might be too toxic to the bees too. So you have to tweaked it a bit to make it work. Now I wonder if tin is better than the aluminum. But AL is easier to work with.
Observed the hive from the outside today. Everything went as usual, bees flying like nothing had happened since last night's oav treatment. Tonight, will do a quick hive check to see if 
the marked queen is still alive after the enhanced oav version at work. Usually I would pick the queen out of her hive. But this time I did not just to test it out. I have stumbled onto something quite amazing.


----------



## BeeBop (Apr 23, 2015)

beepro said:


> Now I wonder if tin is better than the aluminum. But AL is easier to work with.


Better? If you're looking for a metal that melts at an even lower temperature than aluminum, tin is a good choice. (aprox 450F/232C)


----------



## beepro (Dec 31, 2012)

Tin is for a later version. AL is better to work with because you can fold and
shape it into whatever form you like. In this case, it is cheap and available in your everyday household
materials to use.


----------

