# OA Question



## Dave W (Aug 3, 2002)

Here is a method to prepare OA solution:

Prepare a 3.2% OA solution, by adding 44.8 g (1.6 oz) oxalic acid dehydrate (99% purity; 71.4% oxalic acid) to 1 liter (ca. 1 qt) of a 50% sucrose solution (w/v).

What does "99% purity; 71.4% oxalic acid" mean?


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## BULLSEYE BILL (Oct 2, 2002)

I wonder how many have tried the OA anhydrate (sp) (the other OA) instead of dehydrate by mistake and had poor drop rates?


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## George Fergusson (May 19, 2005)

You considering dribbling Dave?

The solution I used:

1 pint water
1 pint sugar
7 level teaspoons OA

>I wonder how many have tried the OA anhydrate

Dunno BB, the container I got (I had a hard time finding it) just says Oxalic Acid. Seemed to work..

George-


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## Dave W (Aug 3, 2002)

Is the OA we buy in a hardware store (wood bleach) 99% pure? Or is it only 71.4% oxalic acid?


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## Kieck (Dec 2, 2005)

I think the 99% purity refers to the presence of other chemicals in the solution. The 71.4% would refer to the amount of acid in the solution. The rest is the solvent, likely water.


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## Dave W (Aug 3, 2002)

Jon, How can 71.4% refer to the amount of acid in the solution, the solution has not been made, yet.

I thought 3.2% was the amount of acid in the solution.

[ December 23, 2005, 03:20 PM: Message edited by: Dave W ]


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## Kieck (Dec 2, 2005)

As I understand acids, all acids have a some water in them. For example, muratic acid is HCl, but within a specific range of concentrations. The rest of the "stuff" in it is water.

The 3.2%, I think, is what your final concentration is after you dilute it still more.


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## Dave W (Aug 3, 2002)

Using the original statement, is this statement true?

Wood bleach oaxlic acid crystals contain 71.4% oxalic acid, and that OA is 99% pure.


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## drobbins (Jun 1, 2005)

DaveW

because of this specific question I got my OA here

http://www.chemistrystore.com/oxalic_acid.htm

I don't know if it's any different
It does seem most folks using OA get it from the hardware store

Dave


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## George Fergusson (May 19, 2005)

Thanks dr, I think I'll obtain some of that. The package I bought (a pint plastic jar) just says "Oxalic Acid Wood Bleach" with the only small print talking about not to eat it or get it on your skin. If rash occurs, discontinue (why not say "stop"??) use, etc. It's *probably* the right stuff, but I'd rather be sure.

So Davew, you planning on a dribble treatment or is this a purely intellectual exercise?


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## pgg (Jun 19, 2005)

George, I wrote down your solution recipe. Are there certain areas of the hive that you dribble the solution on? I used Api-life in the fall but it was too cool to get good results, so I'm looking for a teatment that is not temp. dependent.

Pat


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## George Fergusson (May 19, 2005)

I pretty much dribbled the recommended 5ml of solution in between each pair of frames- 25ml per deep, both deeps for a maximum per hive of 50ml of solution. If there were bees on the outside of the outer frame I dribbled a little down there too. I used 25ml syringes. I got the recipe from Bill Truesdell, a beekeeper near here in Maine. He gave a talk at a local beekeeper's association meeting last fall.

The solution should be warm but not hot, nor cold, but just right. It took a little practice to get good at dribblng evenly, but turned out to be pretty fast and easy. I did mine in early November, the temperature was around 40 F or so. The bees were active but not flying much.

It killed a few bees. Probably drowned them. Not a lot, maybe a dozen or so per hive, sometimes less. It killed a LOT of mites. I don't plan to do it again except as an emergency fall-back solution. If you're going to do it, give a search on this site for other suggestions.

George-


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## sqkcrk (Dec 10, 2005)

The recipe that I was given was 5 gallons water, 25 lbs of sugar and 1 lb of OA. The guy that I helped this summer who was using OA didn't measure how much he used, but did use some common sense about over wetting the cluster. He thought that that method of treatment would do the job. I'm sure that many of you will have opinions to share.

On another topic. People are always talking about beekeepers (and other farmers) who think that if you are supposed to use a certain amount of any treatment chemical that twice that amount should do even better. Well apparently we aren't the only ones. The people administering the Bird Flu Vaccine are finding that the virus has adapted or mutated already. They are saying that perhaps they should have used a stronger dose. That if they had used a stronger dose then this mutation wouldn't have occured. Sound familiar?

Mark


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## Dave W (Aug 3, 2002)

drobbins . . .

>because of this specific question I got my OA here . . .

Do you KNOW what you GOT? Is it 99%, 71.4%, or 50% pure? Knowing would allow you to adjust formula to get a 3.2% final "working" solution (if you think 3.2% is important).


Im going to guess that no one knows what "99% purity; 71.4% oxalic acid" mean? Or cares!


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## Michael Bush (Aug 2, 2002)

>Im going to guess that no one knows what "99% purity; 71.4% oxalic acid" mean? Or cares! 

Basically. You're right. When I was using it I bought the wood bleach and it worked fine. 

But, if I were guessing, and I am, I think it has to do with the amount of water in a very hydrophillic compound. In other words I think it means that it's 99% pure Oxalic acid with 28.6% water absorbed into it.

Part of the problem of getting an accurate measurment by weight is the water absorbtion of the Oxalic acid.

I just measured by volume, verified, when I first opened the package, by weight.


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## drobbins (Jun 1, 2005)

DaveW,

no, I don't know
I assumed from a chemical supply house it would be pure (if you ignore any water absorbed in it)
I would also expect it to be close to dry
I was a little concerned the stuff from the hardware store might have other ingredients
no real reason to suspect that
it just worried me a little
I never found it at the hardware store so I didn't get to look at the label
It certainly seems to work fine for most folks
of course the fact that the guy with the brown pants brought mine right to my door played into it as well









Dave

ps: I'm aware that from a "real" chemical supply house you can pay extra for "pure" grades of things

http://www.chemistrystore.com

didn't offer such an option, nor would I have used it

[ December 27, 2005, 12:11 PM: Message edited by: drobbins ]


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## ninjai_fanatic (Jan 22, 2006)

oh.. i should've known and should've looked in this forum first. 
Took down the recipe as well George, my dad and I are going to start treating our bees soon and want to use OA instead of Apistan strips. 
Thanks!


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## David VanderDussen (May 3, 2005)

Dave W:
Oxalic acid dihydrate is the answer to the 71.4% oxalic acid question. The oxalic acid molecule is accompanied by two water molecules, the "dihydrate" portion of the substance. The atomic mass of the oxalic acid (H2C2O4)is 90, the two water molecules 2(H2O)is 36, for a total mass of 126. 90 divided by 126 expressed as a percentage is 71.4.

The label is stating 99% pure oxalic acid dihydrate, so up to 1% may be other chemicals. 

Since the oxalic acid dihydrate is the most commonly available form, when Canada applied for its OA registration it is based on a 3.5% solution on OA dihydrate: 35 grams mixed in with 1 liter of 50/50 sugar water solution. The pure OA in the solution would be 25 grams (71.4% of 35 grams) per liter. 

regards,
David v


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## George Fergusson (May 19, 2005)

We knew that David... No we didn't. I knew I shoulda paid better attention in Chemistry class.


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## Dick Allen (Sep 4, 2004)

Clear, concise, and straight forward. Thanks David v.


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## drobbins (Jun 1, 2005)

DaveW
actually, given David VanderDussens exellent explanation, I do know
look at this page where I got mine

http://www.chemistrystore.com/oxalic_acid.htm 

has a chemical formula of C2H2O4
so it sounds like the stuff I got is not hydrated with water
which means a gram of it contains more oxalic acid
which may explain why it seemed to work so well for me















where did you get your recipe?
did they mention if they were using the stuff from the hardware store?

Dave

[ January 24, 2006, 02:04 PM: Message edited by: drobbins ]


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## mwjohnson (Nov 19, 2004)

This thread is a good one,but I'm STILL confused.

I would like to measure 35g of OA.I don't have a good scale,and need an easy volume measure that I can use,say teaspoon/tablespoons or something?

I thought that a teaspoon of OA dihydrate was somewhere around 1.5g? IF so,doesn't George's solution seem a little on the weak side?

Could be my math....so what volume should I use to measure 35g , to use in 1 liter of 1:1 syrup?

Thanks


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## Finman (Nov 5, 2004)

.
A good digital kitchen scale is value of 20$. 
Accuracy is 1 g. 

It has grammas and pounds.

It is worth to bye. http://www.1800scales.com/VMC/img_vw_312.jpg

.


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## iddee (Jun 21, 2005)

MW, one ounce is 28.5 gram. 1 1/4 ounce by weight or volume should be very close to 35 grams.


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## Finman (Nov 5, 2004)

. If you put 7,5 ounce oxalic + 100 ounce water + 100 ounce sugar it is same consentration.

It is easy and safe to measure with kitchen balance. All in one cup.

.


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## mwjohnson (Nov 19, 2004)

Thank you
I didn't realize I could just use the old "a pint's a pound thing".

It's just that I'm still a liiitle nervous about the whole idea,still seems kinda harsh,and wanted to ask.

Oh yeah,one more dumb question.









Do the bee's HAVE to be clustered,or can I trickle on a warmish day(50-60deg.F),if they have broken cluster?

Mark


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## Finman (Nov 5, 2004)

.
40 F is very good. Bees are in the ball and do not attach. If day is too fine they start to protect their hive. 

You may give syrup even 14 F but it is not nice to your fingers. 50 F is too much because bees try to attach.

When bees have get oxalic they wake up, ball breaks and bees clean the hive. They will calm down in couple of days.

They bring dead bees out but they have died around hives before trickling.

Method is very safe.
.


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## mwjohnson (Nov 19, 2004)

Thanks again Finman...
Mark


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## Axtmann (Dec 29, 2002)

If you have no scale available you can measure with a syringe. Go to a pharmachie and ask for a 10ml plastic syringe (is very cheep) cut the bottom of and fill the syringe with OA. 1ml = 1gram, 2ml = 2grams and so on. I tested it and it pretty close. With 35 grams youre might be 1gram +/- out.


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