Beemaster's International Beekeeping Forum
BEEKEEPING LEARNING CENTER => DISEASE & PEST CONTROL => Topic started by: JWChesnut on December 09, 2010, 06:40:27 pm
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I vapor treated a 2 deep hive with approx 2 grams (two 1/2 inch end cap measures) of Oxalic Acid-- Hardware store wood bleach brand. My vapor is created in a copper pipe slowly heated with a propane torch. Vapor was introduced via a reduced entrance cleat, and hive was fumigated for 10 min by closing the cleat with paper towelling. Hive is in sunny coastal California, mid 50's F. on day of treatment, upper 30's at night
Two days out I have approximately 50% of the hive dead on my Screen Bottom Board. I only have about 2 covered frames. Uncertain on the queen.
Anyone else have major die-off of this scale from 2 gram fumigations.
I have minimal experience with Oxalic, and was not expecting this outcome. What did I do wrong?
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That sounds about right for two deeps. Maybe you sealed it up too well... I don't know. I have not heard of such a bad outcome from the proper amount, and that sounds about right from my memory.
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1gram per box (deep) is the usual dose so it looks like you did well there. I'm wondering if your OA is pure? I've never had that happen to me.
Scott
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I didn't have that particular problem, but I did one year kill 4 out of 5 queens by doing that. :roll:
Somehow, will never know what I did wrong, cuz I won't do it again.
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2 grams for 2 deeps is correct. Please don't take this the wrong way, but are you confident you used 2 grams? I know grams can be challenging at times. Two grams fits in a 1/2" copper cap.
(http://www.bushkillfarms.com/gallery2/d/1142-2/vapor4.jpg)
It has been years since I vaporized, but I never had any major die off when I did.
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I vapor treated a 2 deep hive with approx 2 grams (two 1/2 inch end cap measures) of Oxalic Acid-- Hardware store wood bleach brand. My vapor is created in a copper pipe slowly heated with a propane torch. Vapor was introduced via a reduced entrance cleat, and hive was fumigated for 10 min by closing the cleat with paper towelling. Hive is in sunny coastal California, mid 50's F. on day of treatment, upper 30's at night
Two days out I have approximately 50% of the hive dead on my Screen Bottom Board. I only have about 2 covered frames. Uncertain on the queen.
Anyone else have major die-off of this scale from 2 gram fumigations.
I have minimal experience with Oxalic, and was not expecting this outcome. What did I do wrong?
2- 1/2 ends caps would be a double dose
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good catch danno, I missed that.
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please post a photo of the label on the acid you used.
deknow
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Oxalic source was
Savogran
Oxalic Acid Wood Bleach
Norwood, Mass 02062
in a 12 ounce plastic container
(http://img72.imageshack.us/img72/1519/img0330je.th.jpg) (http://img72.imageshack.us/i/img0330je.jpg/)
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That is the same brand I used. It was a while ago, so it doesn't mean it hasn't changed though
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What did I do wrong?
I vapor treated......
You need an explanation. :shock:
;)
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What about the pipe? Did it have anything else in it or on it? did you use something to glue the joints?
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I only used the pipe, and only used vapor when I used Oxalic and it was very effective against mites and had no noticeable side effects. I'm sure, however, that it upset the microbial balance of the hive, but this does not seem to be what you experienced.
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I used the same brand of OA, but used a commercial vaporizer on my hives. No losses.
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In research they used up to 5 grams with no loss I think 10 minutes is to long. The research I've read said 2 or 3 minutes.I also wonder if the bees had another issue. I've treated over 100 hives and no die off.
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I actually keep my hives closed up for 15 minutes. Haven't had a problem.
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What is the concentration of the oxalic acid that is typically used when treating hives? I purchased some which is 100% oxalic acid by weight.
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That is the right stuff.
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Good, thanks. We've been having really hard frosts lately so it won't be too long until the hives are broodless and I can actually administer the vapor.
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temperature too high and OA vapor too fast and too hot, when vaporazing OA you have a FA ina a smoke, CO2 olso so maybe you unfortunatley put in a anestezia you bees. dr.Bogdanov says that maximum amount for safe treatman whit OA is a 5g for a 2 depp box of a LR hive. detail is on this site http://www.agroscope.admin.ch/imkerei/00316/00329/02081/index.html?lang=de (http://www.agroscope.admin.ch/imkerei/00316/00329/02081/index.html?lang=de) . i use a OA vaporizer on a car battery.
it have 2 nice articles about OA vaporizing on bottom is advantage of sublimation and 7nt from bottom is paper that says that not all vaporizing tehniques have good resoult.
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10 minutes of fumigation is too much, it will take less than one minute. it should be the alternative to drop oxalic acid solution between the frame-spaces and it will take 3 minutes in that way :-P
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first a snip...
Oxalic Acid-- Hardware store wood bleach brand.
tecumseh...
I have not use oxalic vapor in a several years but when I did I obtained 99.6% pure oxalic on the net at a very low price. although folks did suggest the wood bleach route to me when I was considering the oxalic vapor method I am a bit to weary of what else might be in there for myself to use such a product in my hive. I think too much of my own family (who do eat my honey) and my 'girls' to take those kinds of risk.
If my recall is correct the two grams of oxalic would totally vaporize using an engine block heater in just about two minutes... should be much faster if you were using a pipe and plumber's torch.
I never saw anything in my experience in using vaporized oxalic that even approaches you description.
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Oxalic acid sublimes from a round 101C however around 157C it decomposes into CARBON MONOXIDE CO2 and H20
using a propane torch is not temperature controlled and so rapid heating of the tube could have converted a signinficant proportion to CARBON MONOXIDE.
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Was their any lead solder on the pipe?
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Oxalic acid sublimes from a round 101C however around 157C it decomposes into CARBON MONOXIDE CO2 and H20
using a propane torch is not temperature controlled and so rapid heating of the tube could have converted a signinficant proportion to CARBON MONOXIDE.
I am with derekm on this. Using an uncontrolled method of heating is asking for trouble in my opinion.