# OAV Treatment Problem



## psm1212 (Feb 9, 2016)

I let mine run for 3 1/2 minutes. Also, my rechargeable battery pack is only good for about 3 treatments before it starts getting weak and requiring longer periods of time or a recharge. The way I know it is weaker is that it starts to leave powder in the tray.


----------



## Amiaji (Jun 8, 2017)

I ran quite few tests with my battery pack when I first got the vaporizer. It was still going strong after 10 tests.

Also there is no powder left in the vaporizer itself but on the board all around it.


----------



## Grins (May 24, 2016)

The intermittent part is the head scratcher for me, could it be a connection problem to the battery? I'm trying to think of what could cause one cycle to go well, the next not. It just seems the vaporizer isn't getting enough juice to sublimate the whole amount every now and again.
Edit: If the picture is what you see after a failed cycle I wonder if you're leaving water in the cup that might splash the OA out as it boils off.


----------



## Amiaji (Jun 8, 2017)

I make sure the vaporizer is dry after each treatment.

Also every time I have tested it laying on the picnic table it performs perfectly. the only time I have a problem is when it is inside the hive.


----------



## Grins (May 24, 2016)

Amiaji said:


> I make sure the vaporizer is dry after each treatment.
> 
> Also every time I have tested it laying on the picnic table it performs perfectly. the only time I have a problem is when it is inside the hive.


Hmm, something appears to be causing the OA to splash out. Do you shove a stick in to clear dead bees or low hanging comb? Perhaps a bit of wax is dropping into the cup and causing the splash, the cup is blackened as though it's cooking something more than OA. How much space is there between the vaporizer and bottom of the frames?


----------



## Stephenpbird (May 22, 2011)

How much OA are you using? If there is too much in my vaporizer I get the same result as in your picture. Are you sure your doses of OA are the same every time for every treatment.
The bees are not affected by a little extra OA but the efficiency of the vaporizer is.


----------



## Amiaji (Jun 8, 2017)

Grins said:


> Hmm, something appears to be causing the OA to splash out. Do you shove a stick in to clear dead bees or low hanging comb? Perhaps a bit of wax is dropping into the cup and causing the splash, the cup is blackened as though it's cooking something more than OA. How much space is there between the vaporizer and bottom of the frames?



There is probably an inch and a half between the vaporizer and the bottom of the frames. I insert the vaporizer where the oil tray would be which is below the screened bottom.




Stephenpbird said:


> How much OA are you using? If there is too much in my vaporizer I get the same result as in your picture. Are you sure your doses of OA are the same every time for every treatment.
> The bees are not affected by a little extra OA but the efficiency of the vaporizer is.



I use 2 grams on the 2 larger hives and 1 gram on the 2 smaller hives.


----------



## Grins (May 24, 2016)

I'm stumped. I hope someone nails it down for you.


----------



## John Davis (Apr 29, 2014)

Below the screened bottom means the vapors are probably condensing on the screen and falling back down around the pan. The screen is acting as a heat sink, most of the vapors are not getting through it up into the hive.


----------



## Amiaji (Jun 8, 2017)

John Davis said:


> Below the screened bottom means the vapors are probably condensing on the screen and falling back down around the pan. The screen is acting as a heat sink, most of the vapors are not getting through it up into the hive.


I wondered if this might be the case but it seems strange that it would only do it some of the time.


----------



## DaisyNJ (Aug 3, 2015)

How does that powder "feel".. is it granular like the powder you put in the beginning or is it very fine like its vaporized but rained back down ?


----------



## Amiaji (Jun 8, 2017)

DaisyNJ said:


> How does that powder "feel".. is it granular like the powder you put in the beginning or is it very fine like its vaporized but rained back down ?


I didn't really feel it but it did look rather fluffy. I'm giving them one more treatment next week I'll feel it and see if there is a difference.


----------



## DaisyNJ (Aug 3, 2015)

Amiaji said:


> I didn't really feel it but it did look rather fluffy. I'm giving them one more treatment next week I'll feel it and see if there is a difference.


I have a silly theory that its vaporizing, hitting the cluster thats packed tightly (almost like a ceiling), swirls around, hits the bottom and condenses. Give a puff of smoke into the entrance before you vaporize and see if that makes any difference.


----------



## dudelt (Mar 18, 2013)

I have seen the same effect and my thought on the cause is the water that is naturally absorbed by the OA. When the water boils, it splashes some of the powder out of the vaporizer. OA will absorb water from the atmosphere so there is always some water in the OA. The more that is absorbed, the more splashing you get.


----------



## Grins (May 24, 2016)

DaisyNJ said:


> I have a silly theory that its vaporizing, hitting the cluster thats packed tightly (almost like a ceiling), swirls around, hits the bottom and condenses. Give a puff of smoke into the entrance before you vaporize and see if that makes any difference.


If the powder around the vaporizer is fluffy, like ash, Daisy has nailed it. The sublimated vapor precipitated, perhaps against the screen, and fell down around the column of rising vapor.


----------



## Amiaji (Jun 8, 2017)

DaisyNJ said:


> I have a silly theory that its vaporizing, hitting the cluster thats packed tightly (almost like a ceiling), swirls around, hits the bottom and condenses. Give a puff of smoke into the entrance before you vaporize and see if that makes any difference.





Grins said:


> If the powder around the vaporizer is fluffy, like ash, Daisy has nailed it. The sublimated vapor precipitated, perhaps against the screen, and fell down around the column of rising vapor.


It is certainly looking like that is the problem. I was really hoping I could use it under the screen and not have to pull out the entrance reducer every time. I wonder if I could measure how much is left on the board and compensate for it by putting a bit more in?


----------



## Mike Gillmore (Feb 25, 2006)

I vaporize all of my hives under a screen and will occasionally see the same fluffy white powder on the board after vaporizing. I don't have a definite answer to your question, but I'm confident that the treatment will still be effective. Even on those colonies that have powder on the board the hive is filled with vapor and I can see it escaping through cracks in the boxes and at the cover. 

I've noticed that when the OA is placed loosely in the pan it sometimes has a tendency when heated to create hollow areas while it is vaporizing. When the domed pieces fall and hit the hot pan it can sizzle and spray powder out of the pan. I've made it routine now to lightly pack the OA powder down into the pan. That seems to help the OA liquify more evenly and reduces the amount of powder that is scattered on the board. 

I'm sure some of it has to do with crystals collecting on the screen and frames above the pan. I've noticed at times when I return a couple days later to pull the trays and check the mite drops that sometimes there will be a small area of white powder in the same place the vaporizer pan was located when treating. Probably just the bees scrubbing things up and removing the crystals.


----------



## snl (Nov 20, 2009)

Vaporize outside the hive on a concrete pad and tell us what you see. 
Also try vaporizing using a running car battery. Sometimes that occurs with a weak battery or with very damp OA.


----------



## Amiaji (Jun 8, 2017)

Mike Gillmore said:


> I vaporize all of my hives under a screen and will occasionally see the same fluffy white powder on the board after vaporizing. I don't have a definite answer to your question, but I'm confident that the treatment will still be effective. Even on those colonies that have powder on the board the hive is filled with vapor and I can see it escaping through cracks in the boxes and at the cover.


There is definitely vapor all throughout the hive.



Mike Gillmore said:


> I've noticed that when the OA is placed loosely in the pan it sometimes has a tendency when heated to create hollow areas while it is vaporizing. When the domed pieces fall and hit the hot pan it can sizzle and spray powder out of the pan. I've made it routine now to lightly pack the OA powder down into the pan. That seems to help the OA liquify more evenly and reduces the amount of powder that is scattered on the board.


I do spread it around and lightly pack it down.



Mike Gillmore said:


> I'm sure some of it has to do with crystals collecting on the screen and frames above the pan. I've noticed at times when I return a couple days later to pull the trays and check the mite drops that sometimes there will be a small area of white powder in the same place the vaporizer pan was located when treating. Probably just the bees scrubbing things up and removing the crystals.


It does seem to be that some of the vapor is crystallizing on the screen and then falling back down on the board. The question is is it enough to make a difference. When I treat them next week I will measure the amount left behind on the board.



snl said:


> Vaporize outside the hive on a concrete pad and tell us what you see.
> Also try vaporizing using a running car battery. Sometimes that occurs with a weak battery or with very damp OA.


When I first got the vaporizer I did 10l test runs with it sitting on the picnic table and it performed flawlessly. I also tested it yesterday morning before treating the hives and it worked fine. I don't think it is the vaporizer or the battery pack.


----------



## enjambres (Jun 30, 2013)

Doing it under the screen is the problem. I tried and tried to make that work and never succeeded. Now I slide the vaporizer in the hive on top of the screen and almost never have a fail. (I use a Varrox, too.)

I use a thin sheet of aluminum (rimless cookie sheets are what I have been using, but I am going to have some similar sheets made and re-claim the kitchen equipment). I find that if the pan sits on the cookie sheet in cool weather I get more "snow" and less-perfect burn. If I make a point of wedging the paper towels (what I use to close up the front entrance) so that the back end of the wand is pushed slightly down, raising the pot-end of the wand up about a quarter of inch, or less, then I almost never have burn-failure. It becomes much more important to do this when treating below 50F.

It seems like a such a good idea for protecting the bees, to use the wand below the screen, but it was a complete bust for me. However, I almost never find a cooked-up bee in the pot. I vaporized steadily in multiple yards all day today, without a single one. I do find that adding a 2" high blind shim under my lowest box not only provides me with the benefits of a slatted rack, but also raises up the bottom edge of the lowest frames a bit farther away from the pan, an added measuring of safety. However, many of the hives I OAV-ed today have the standard config, and I had no issues. It just takes a bit more attention and I think the bees in the lower box aren't as happy, being so close to the source. I smoke the bees lightly before treating to shift them upwards and loosen the cluster; I like to hear a bit of a buzz.

Keep your OA as dry as possible. I decant the contents of original container into smaller, tightly sealed, zip-locks as soon as I open a new can. That way I only have a portion open at a time. (I do close the bag between measuring out a dose, but still, OA is extremely hydrophilic, and often like today it's a bit damp out.) 

I measure very carefully using the dip-and-sweep method. I routinely burn a full teaspoon (4-box dose) in my Varrox and occasionally, even 1.25 teaspoons for five-box stacks. I add 10 second to the power-on burn period with the 5-box dose.

Also, did you find and remove the tiny plastic measuring scoops that may be taped under the wings of the wand?

Nancy


----------



## Amiaji (Jun 8, 2017)

Next time I treat I am going to measure the amount left on the board. Perhaps I can compensate for it. I did one treatment without sealing up the upper entrance and I had vapor coming out so i know it is getting in the hive. 

And yes I found the two scoops taped to the underside of the wings. I'm not sure if its the plastic the scoop is made of or the acid but it is funny how the powder will not stick to the scoop. If you tap the scoop the powder will turn into a ball and just rotate around in the scoop.


----------



## Hogback Honey (Oct 29, 2013)

Thanks SNL, I just vaporized my 4 hives this morning. The damp OA must be causing my problem. Last time I vaporized the very first time there was some OA still in the cup, the other 3 went without a hitch. Today, it was the 2nd and 4th hives I vaporized where there was still OA in the cup, on the last hive it seemed like a lot. I drive up to my hives and use my car battery, next time I'll leave it running, see if that makes a difference.


----------



## Barhopper (Mar 5, 2015)

dudelt said:


> I have seen the same effect and my thought on the cause is the water that is naturally absorbed by the OA. When the water boils, it splashes some of the powder out of the vaporizer. OA will absorb water from the atmosphere so there is always some water in the OA. The more that is absorbed, the more splashing you get.


Bingo!


----------

