Oxalic Vapor disaster

JWChesnut · December 09, 2010, 06:40:27 PM

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?

Michael Bush · December 10, 2010, 08:48:46 AM

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.

hardwood · December 10, 2010, 09:04:12 AM

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

Scadsobees · December 10, 2010, 09:14:18 AM

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.

Robo · December 10, 2010, 10:02:22 AM

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.

It has been years since I vaporized, but I never had any major die off when I did.

danno · December 10, 2010, 10:32:23 AM

Quote from: JWChesnut on December 09, 2010, 06:40:27 PM
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

Robo · December 10, 2010, 10:42:54 AM

good catch danno, I missed that.

deknow · December 10, 2010, 11:02:40 AM

please post a photo of the label on the acid you used.

deknow

JWChesnut · December 10, 2010, 05:29:02 PM

Oxalic source was
Savogran
Oxalic Acid Wood Bleach
Norwood, Mass 02062

in a 12 ounce plastic container

Robo · December 10, 2010, 06:41:20 PM

That is the same brand I used. It was a while ago, so it doesn't mean it hasn't changed though

BjornBee · December 10, 2010, 08:02:08 PM

Quote from: JWChesnut on December 09, 2010, 06:40:27 PM
What did I do wrong?

Quote from: JWChesnut on December 09, 2010, 06:40:27 PM
I vapor treated......

You need an explanation. :shock:

;)

alfred · December 17, 2010, 11:47:04 AM

What about the pipe? Did it have anything else in it or on it? did you use something to glue the joints?

Michael Bush · December 17, 2010, 09:12:56 PM

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.

cam · January 11, 2011, 03:53:16 PM

I used the same brand of OA, but used a commercial vaporizer on my hives. No losses.

hahunltd · January 31, 2011, 10:30:57 AM

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.

cam · January 31, 2011, 04:26:43 PM

I actually keep my hives closed up for 15 minutes. Haven't had a problem.

rwurster · October 28, 2012, 03:35:15 AM

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.

Robo · October 28, 2012, 08:32:43 AM

That is the right stuff.

rwurster · October 28, 2012, 11:34:20 AM

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.

saperica · October 28, 2012, 11:47:44 AM

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 . 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.