Simple oxalic acid vaporizer set-up

[tjc1]

IF you have screened bottom boards on your hives and IF you have your hives up on cinder blocks or a similar arrangement that allows clear underneath access at the back and sides, this set-up might be of interest.

You will need an Italian style coffee pot, a piece of luan plywood, and a propane torch (an extension tube for the torch may prove helpful - see photo).

Cut the luan to the size of your plastic bottom board. Take the bottom half of the coffee pot and center it on the luan board, and scribe around the opening with a pencil.  If you don't have a hole cutter, use a drill to drill holes around the inside of the circle, just touching the pencil line. When you have gone all the way around, take a box knife and carefully cut the bits between drill holes. Trim as necessary until you can screw the coffee pot bottom into the hole.










Add 1/4 teaspoon of oxalic acid to the pot for each story of the hive being treated. Replace the plastic bottom board on the hive with this fuming board. Stop up the hive entrance. Apply heat with the torch to the bottom of the pot for about 2 minutes. Let the hive sit for 5 minutes before removing the fume board and replacing the plastic bottom board.

[Michael Bush]

I wouldn't ruin a wonderful coffee maker... a simple 3/4" brass pipe with an ell and a cap works fine.

[OldMech]

  I have read (Yeah I know) that too much heat converts the OA to formic.. how do you control the heat with the torch?

[tjc1]

The coffee maker was a very old one - and long unused - but you can buy them new for $10 - $15. Also, since I was mounting it on the luan, I figured something larger with the bottom further away from the luan would avoid burning the wood.

Interesting question about the oxalic to formic conversion - if it's true, it has got to be an issue for any of the gizmo's I've seen that use a torch as heat source - or maybe even a glow plug. I can see how the expensive purchased units might be temp regulated - anyone else have any info on this temperature question?

[little john]

The major problem with any apparatus involving a gas torch is that you'll be too d*mn close to the vapour when it's being generated.  All it would take is a small puff to escape through a crack to spoil your day.

Much safer to operate a vapouriser from the end of six feet of cable, and upwind of the hive.

Formic acid can never be produced in any significant amount from heating Oxalic Acid at atmospheric pressure. Once it reaches it's vapourisation temperature - it vapourises completely - leaving only tiny amounts of impurities (heavy metals - mainly iron salts) behind.

LJ

[Michael Bush]

> I have read (Yeah I know) that too much heat converts the OA to formic..

Formic kills mites too...  The biggest issue with using a torch as opposed to a remote electric method is that you're standing next to the source of the vapor... and a shift in wind can have a dramatic affect the human...

[sc-bee]

Way too much trouble IMHO...

[tjc1]

Yes, well, being a skinflint yankee and not wanting to spend $150 on a device I'll only use twice a year on two hives.... I tried a Youtube suggestion of using an electric immersible heater coil (for making tea), and it worked great - once - they are made to burn out if plugged in un-immersed... The comments about being too close to the source are well-taken. I should get a respirator mask to wear while using it. Otherwise, it was easy to make and worked real well.

[sc-bee]

I hear the ones burning out are the 110v and not the 12v. I started to go the homemade coffee immersion route but I got a good deal on the varrox @ oxavap. It arrived today and is very heavy duty and well constructed. I just don't like the propane idea.

[OldMech]

  All it would take is a small puff to escape through a crack to spoil your day.

   I got in  a bit of a hurry this fall treating hives with my Varrox...  Pulled the rag too soon to move on and got a decent huff...   Nope, didnt ruin my day, ruined about fifteen seconds while i coughed three or four times and QUICKLY moved upwind... was fine after that....  first time I have ever gotten a whif of it, even after ALL the treatments I have done...   It was anticlimactic...  Not good, but certainly not the near death experience I expected.

   Good to know that if it gets too hot/formic that it wont matter, didnt realize that. Thank you Michael.

[little john]

In a sense - getting a whiff of oxalic acid vapour is actually not a bad thing to have happened .... because, as you immediately discovered, it's quite impossible to stand your ground and 'tolerate' it. "Quickly moving upwind" quite probably saved possible damage to your eyes.

When I first started to test DIY vapourisers some years ago I received the slightest 'whiff' of the stuff - and with hindsight that was the best thing which could have happened - 'cause it created in me the inflexible precaution of always staying a good distance away when using it, and always upwind.

It's not unlike the scenario of children touching hot objects for the first time, in order to know what 'hot' really means. The learning process can indeed be painful.

And so I introduce OAV through a purpose-made hole in the hive, and never employ cloths, or anything similar which would cause me to bend down nearer to the box.

Myself, I don't wear any protection gear when applying OAV, but then I don't have guards fitted to my table router or saw either - but - I treat them all equally, with ABSOLUTE respect, as if I were working with red-hot steel.

LJ

[GSF]

Same here Little John, I've never breathed it in over a "prolonged" period. Once it hits you - you move.