My Oxalic Acid Vaporizer

[mmmooretx]

I have been following this thread with a particular interest, I plan on building one of these units this winter but for now I was wondering if a battery charger would work as an energy source, set on 12 volt or even 6 volts perhaps?

A battery charger with a start function yes, a trickle charger no. Basically you need to look at the chargers output in amps. Usually it will be the larger ones that say quick charge or something like that.

shadow-cw,
OK I will have to think on that one for my implementation. Thanks again for your time and support. I'll probably post something tonight on what I learn. Once I figure out my hardware I will need to decide on a battery or charger since my hives are in my back yard.

[Daniel Y]

My understanding is the OA vapor will not kill Tracheal mites.

I have seen it mentioned twice now that it does, many places it is claimed only to deal with Varroa. I can't seem to get the tracheal mite claim confirmed. Yet. I sure hope it is true because I am in the process of making one of these foggers. I like the window. I was trying to figure out how to make a tray out of 2" aluminum rod to slide into the entrance. I like this one better. Thanks for sharing it. An extra thanks for the details in how it is wired.

[crofter]

Some chargers will not deliver any current unless they sense a load of proper polarity. Some glow plugs must be used with their controller or will burn out allmost immediately. I use VW plugs direct on 12 volts and have left them on overnight (not intentionally) and they survive. Mine draw 12 amps each. Best to source a plug type you know will work with direct battery voltage.

[mmmooretx]

OK I got my Autolite 1104 today and it measures 0.8 ohms which calculates to 15 amps at 12 vdc, or 17.5 amps at 13.8 vdc. I have checked and if I grind the threads off and it will slip inside some 1/2" SS 304 tubing I have. If I grind 2 short splits in the tubing, no longer than the the threads on the glow plug, wrap the ex-thread area with aluminum foil for a seal, with some plumbers tape for handle attachment and a hose clamp, I think I will have it. Now if the Autolite 1104 unit does not need a controller to keep it from burning out I will have an OA vaporizer soon. I have a 30 amp power supply I can use that also has a current limiter in it.

[WWW]

That is so coooool Mike, please keep us updated on your progress.

[crofter]

mmmooretx, that resistance measured cold, will increase considerably as the element heats so the current draw will drop. I am quite sure you will be good to go! I spliced a deep socket onto a 1/4 tube to be able to reach and screw the glo plug into the barrel of mine. Your way is a lot easier to install and wire. Haven't used mine yet but will in November.

[mmmooretx]

I am ready to assemble mine and will do a pictures or a video. I had flash on an easier way to do it this morning than what I did, but will keep what I did. If I got a 12 X 1.25 tap I could have screwed the glow plug directly into the 1/2" 304 SS tubing!

[shadow-cw]

Cool guys, can' wait to see what everyone builds. Hopefully I can post some pics of my new vaporizer set-up tonight. I ran a few more tests on my 12v set-up and here are some numbers:
12V Interstate full sized battery. 575 cold cranking amps and 720 cranking amps.
12.8V in the battery to start
Air Temp was 70*F
15 sec- 75*F
30 sec- 95*F
45 sec- 127*F
1:00- 164*F
1:15- 200*F
1:30- 238*F
1:45- 277*F
2:00- 315*F
At two minute mark I unpluged it from the battery but the aluminum was still transfering the heat to the combustion chamber. 2:20 the temp hit 365*F. So I'm thinking on my unit I need to unplug around the 1:40 mark to keep from burning the OA. The temperature results were pretty much the same as using the small 12v battery on my John Deere Gator.
12.5V in the battery at the end of the test.
Amp draw was 13.8 at the start and dropped to 11.8 at the 15 second mark.

[mmmooretx]

Great data thanks for sharing. I need to find some OA locally if I can so I can play too. :-D

[shadow-cw]

Ok, I finally have some pics of my new set-up.
Here's the vaporizer assembled and ready for 12v. Aluminum and stainless steel construction. Everything threads together so I can disassemble it for cleaning.
70josx.jpg

Here it is hooked up for 12v. I have a threaded insert on my box so I can easily remove the vaporizer.
6e3i8o.jpg


And here it is setup for use with a propane torch to heat the OA.
fjfar9.jpg

Later on I still have to make a smaller diameter and longer length nozzle so I can use the vaporizer on my nuc boxes. A Nuc Nozzle, lol.

[mmmooretx]

Very nice work!

[WWW]

Sweet setup shadow and excellent craftsmanship , I look forward to your first test run.

[Daniel Y]

Shadow, A couple of questions.
How much clearance is any is between the glow plug element and the aluminum rod?
Did you take into consideration expansion inside the rod when the element heats up or do you want this chamber air tight?
I have the glow plug and aluminum rod and was going to start building one today. But thinking it through I was not sure just what size drill bit to use for boring the portion of the hole for the element to fit into.

Final question. What is a good source for the OA?

[shadow-cw]

Shadow, A couple of questions.
How much clearance is any is between the glow plug element and the aluminum rod?
Did you take into consideration expansion inside the rod when the element heats up or do you want this chamber air tight?
I have the glow plug and aluminum rod and was going to start building one today. But thinking it through I was not sure just what size drill bit to use for boring the portion of the hole for the element to fit into.

Final question. What is a good source for the OA?

Hi Daniel,
The tip of the glow plug will expand some when heated. Hook it up and heat it outside the aluminum rod to start. When the plug cools off take some measurements. I didn't want the tip to touch the aluminum but wanted it close to transfer more heat to the aluminum. I did think of air pressure inside the tip chamber, this was another reason I turned the threads off the plug and used a set screw. Gives it just alittle bit of air gap. I have been thinking on some sort of liquid heat transfer system but have not go very deep into it yet. Water will tranfer heat 10X fast/better than air but there might be a pressure issue to deal with.
OA can be found at most local hardware stores. Sold in the paint section as wood bleach. I bought mine on ebay, $12 shipped for 2 pounds.
Hope this helps,
Caleb

[Daniel Y]

One of the more sought after features I have seen mentioned is built in air movement. This video is the example I have seen most commented about.

http://www.youtube.com/watch?v=2NoYE...layer_embedded

I see your glow plug Acid chamber design is extremely adaptable to many other configurations.

I have seen comments of pipe being permanently installed in hive bodies where the vaporizer can then simply be fit and the acid treatment administered. the pipe is then capped until needed again. Copper or brass pipe was suggested in that design as well. Possibly aluminum tubing would be better.

On the heat transfer issue. My first thought was of a grease that is applied to the back of certain integrated circuits that generate excessive heat. the grease makes the transfer of heat to a metal plate higher so the circuit is protected. I am not sure of what the temperature ranges for that specific grease is but I do know such products exist.

Speaking of heat transfer. Do you have any measurements on the cool down of the chamber after the acid has been vaporized. Everything I have seen speaks of the heat up and time it takes to vaporize the acid but I never see where the time to cool down is added.

[shadow-cw]

The heat transfer grease may be a good idea. I'll have to do some research on it. I know some of my high speed flashlights have thermal grease in them.
Read through a couple of pass posts. I wouldn't reccomend brass or copper for the vaporizers. There is a chance of toxic gasses in those two metals.
Everyone has told me to leave the hive closed up for 10 minutes after vaporizing the OA. The aluminum dissipates the heat very fast. It just barely warm to the touch after 10 minutes.
Also I think it would be best to be able to clean the vaporizer from time to time.
A note on air flow too. Once the vapors enter the hive the bees will fan it through out the hive trying to remove it.

[mmmooretx]

I think I would use Anti-Seize to prevent thread galling, especially if you are mating SS & Aluminium.

[shadow-cw]

I think I would use Anti-Seize to prevent thread galling, especially if you are mating SS & Aluminium.

Maybe a good idea but does anyone know is Anti-seize off gasses when heated?

[Daniel Y]

Shadow I can't say about the anti seize and gassing. But would it matter? The threads for the glow plug at least are outside the chamber. As for off gasing of copper or brass. I have never heard a concern about it for plumbers that sweat copper all day long. often in large volumes in confined spaces. I have seen the concern that the introduction of Oxalic Acid changes the chemistry though. At the very least a concern.
I do beleive the forced movement of the vapors is more of a perception thing to the beekeeper than a necessity. But people are attracted to what they are attracted to. Vapors are goign to pretty much dissipate no matter what. But this is not something the average person is goign to know about or rely on. that it blows around just carries a level of comfort to it. I am pretty thrilled with the design as it is.

[Radar]

Glow plugs are pretty robust, I have made 2 vaporizers and have used them on about 40 hives per year for 6 years now, and I have the tip protruding into the crystals with no problems.

The down side is the battery it will only do about 10-12 hives per charge. I know a bigger battery would do more but they are heavy.