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My Oxalic Acid Vaporizer

55K views 114 replies 22 participants last post by  Tim B 
#1 ·
Hi all,
I have been researching oxalic acid vaporizers. This is what I built and wanted your opinions on it. I made everythingg from scrap I had in my shop. The box is a shallow supper that I screwed up and cut the boards too narrow. The first two pics show it set up for use with a portable propane torch. The last pic shows it set up for 12 volt use. All the copper fittings are tig welded for an air tight joint.
Let me know what you think,
Thanks all,
Caleb

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#67 ·
The tip of the glow plug is very corrosion resistant but not sure about specifically to Oxalic. Should be at least equal to stainless steel. That said, it may not be the best practice to have that high a temperature immediately on the oxalic. Something about it flashing to formic and CO and then not able to sublime to the fine oxalic crystal form you want deposited in the hive. Dont make too dinky of holes to charge your furnace; the oxalic powder looks nice and free flowing when you open a new container but I think it gets pretty crumby and lumpy with exposure. A glo plug is only putting out about 125 watts so you have to limit the heat loss where not needed. A couple of layers of glass cloth and a blanket of aluminum foil dont take up too much room but will slow cool down too if you want to do a series.
 
#69 ·
In my experience with a crack pipe and how quickly the OA goes from vapor to CO2/water with only a slight increase of heat I believe that the OA directly contacting the glow plug should be avoided. Ideally I feel the chamber needs to be of enough mass that the OA is brought up to heat in a slower controlled manor and the reservoir should be able to hold this heat until all the OA is vaporized. It is very easy to take the OA into the CO2/water stage and a person can be unaware that this has happened rendering your treatment ineffective. That being said the delivery pipe should also be as short as possible to avoid it cooling too fast and the vapor crystallizing in this delivery pipe. The mass of metal needed to make this glow plug work may work against being able to do multiple hives quickly because of the cooling down time between hives unless the unit can be submerged in water.
 
#70 ·
I have been thinking this exposed tip as well as the overheating issue over for a couple of days. So far here is my main thought. Not arguing just presenting a possibility based upon my knowledge of other materials. The tip of a glow plug is exposed to diesel fuel and any other additives of that, fuel treatments etc. IT is also exposed in an inclosed high pressure chamber. One case to show it can tolerate exposure but it also may be in part due to the environment in which it is exposed.

As for the overheateg. The OA reaches the temperature at which it will vaporize. it then vaporizes and will remove itself from the heat source. There is a very strong case that when free to vaporize it will do so eliminating any concern that ti woudl be overheated. In another example of this water will boil into steam, in in other words vapor. under open conditions the steam will not ever get hotter as it removes itself from the heat source. the only way to get steam hotter than that is to trap it in a chamber. Water in fact can be gotten far above it's boiling point without boiling if ti is put under pressure. Again it is contained. So although OA can be gotten to temperatures that will react in other ways than vaporizing. I would want to know far more about the exact conditions under which this can happen. I have a strong suspicion it cannot happen while simply exposed to the open air. iN open air the OA will have vaporized and been gone long before the element could reach to high of a temperature. Even if all of this is measure in milli seconds of time frame. the Acid will vaporize at the temperature in which it vaporizes unless it is contained in order to be exposed to temperatures higher than that. there is no concern how it will react to higher temperatures than that.

In addition there are already some designs that are demonstrated to work. At most the ideas being discussed here are alterations of those designs.

Mass is a trade off. Retained heat means the next batch is vaporized with less energy. it also means more heat retained making the unit to hot to handle. I have been toying with ideas on how to keep the heat only where it si wanted. glass cloth to insulate fro example. but to insulate just a small pocket of a chamber that holds the acid. this you have quick heating of a very small mass as well as the quick cooling of that same small mass. The heat from the glow plug only has one way to go in effect. and that is into the cup and as a result into the OA.

Anyway back to the real world.

Do to a rocky start (to many projects at once) I have finally ordered the Stainless Stell pipe fittings. Total Cost $14.36 with shipping from buyfittingsonline.com

I got
1- 3/4 inch nipple NPT
1- 3/4 inch 45 degree Elbow NPT

I will be machining an adapter to fit the Elbow and the 1 1/4 inch diameter Aluminum rod that I will make the vapor chamber out of.

I will continue to look for a way to make one of these entirely out of off the shelf parts.

I also ordered a 2 lb bottle of OA on E-bay for $12.50 including shipping.

Still to get is a 2/4 inch galvanized pipe flange for attaching the pipe to the side of the box. I estimate this to cost about $3.00. MY daughter was going by the hardware store today so hopefully she found one.

So for now I have some waiting for orders to arrive as well as some metal turning and drilling to do. I will attempt to keep this as simple as possible for those with at least limited shop availability.
 
#71 ·
Good info Daniel. Sound reasonable. The only thing I can think of that might make a small difference is OA is a compound, H2C2O4. Each one of those elements has a different vaporization temp but Like you said I think it will be measured in miliseconds. Can't wait to see what you build.

I did find this info on OA: http://scientificbeekeeping.com/oxalic-acid-heat-vaporization-and-other-methods-part-2-of-2-parts/

Also I nearly have my smaller nuc nozzle finished. Just have to figure out the proper length. It's 3/8" stainless steel tube, press fitted in to a piece of aluminum thats threaded to fit my 1/2" pipe setup. As you can see in the pic I took some mass out of my 12v combustion chamber to help it heat faster. Just have to test it out.
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#72 ·
Thanks Shadow, I have been wondering about the mass of the chamber myself. It makes since to me that smaller is better both for heating up and cooling down.

The smallest aluminum rod I had laying around was 1.25 inch diameter.as it turns out I cannot mount this on my metal lathe (it is a mini 7X12) due to it holding only up to a 1 inch diameter piece. Grrrrr.

I drilled the chamber on my drill press. The glow plug fits just fine but the hole did not come out centered. I will look for a smaller piece of rod that will fit my lathe and make a new one in the future.

Interesting article. Several points caught my attention. One being that the mite kill according to his chart is nearly identical at 1.4 gram dosage as it is at 2.8. Sort of makes me wonder just how little of a dose is enough. It is a great example of showing how if enough is good more is not better.

I did pay attention to the portion about the Acid vaporizing or decomposing. It does clearly show there is a danger of decomposing the OA rather than vaporizing it by applying heat to quickly. What it does not include is how much is to much heat and in what time period.

In part due to other conversations including private ones with others. I am thinking the problem results from applying the OA to a surface or chamber that has not been allowed to cool adequately. Otherwise some of the vaporizers I have seen seem to vaporize almost immediately.

At any rate heating to quickly is definitely a concern in these designs.

I like the fish hook. The last thing I carved was quite a while back. it was a guitar pick from Mother of Pearl. I made it for a friend who was just starting to learn to play.
 
#73 ·
I made up a vaporizer yesterday. I used two glow plugs so they sit either side of the chamber which is a piece of 1/2 stainless pipe about an inch and a half long with the ends closed and hole cut in the top to fill. Crude but I wanted to observe the process. I note that there is quick recrystalization on parts that are not up to temperature. Looks like hoar frost. After a while as the chamber heats, it does go off into the air. I dont think a length of pipe leading into the hive will give a dependably measured delivery. The propane heated crack pipe shows the same thing unless you heat up the discharge pipe before you heat the area with the powder. It takes a bit of fiddling to get good boil off without having it flash. It is not nice to be that up close and personal with oxalic vapor, so the electric is more user friendly. What I stuck together is not slim enough to go through a standard entrance. In a way I dont want the glow plug exposed to potentially ignite wax inside a hive as they certainly glow a bright yellow for about an inch long. Still meditating!
 
#80 ·
Great info. I'm getting the same "frosting" on parts that are not up to temperature. I don't know if my nuc nozzel will work or not. I'm going to work on a small compact vaporizer that will fit through the entrance. The double glow plug has gave me a few ideas.
 
#74 ·
I finished my chamber glow plug assembly as well as the connection to the box yesterday and today. I am not completely happy with it due to having to resort to some copper fittings. Without the ability to reduce the aluminum rod to be threaded to fit the SS elbow I had to find a slip fitting for the 1 1/4 inch rod. Three fittings total and nearly $30. I am not happy with the cost either.

I can fix the entire problem with using 1 inch aluminum rod in the future which then can be threaded to fit the ss pipe fittings. For now this will work for testing etc. To use it on my hives I will coat the inner surfaces of the copper fittings with epoxy such as JB weld.

Total cost of the assembly is now.

Glow Plug $10.76
1 1/4 inch to 1 inch reducing coupling $6.27
1 inch to 3/4 inch bushing $5.69
3/4 inch slip to 3/4 inch male pipe thread adapter $2.44
2.5 inch piece of 3/4 inch copper pipe. $0.80 ( I had to buy 2 feet of pipe for $7.69 for only 2.5 inches)
3/8 inch copper cap to make a measuring scoop $1.38 including tax
3/4 inch galvanized pipe flange $8.00
3/4 in SS 45 degree elbow $5.98
3/4 inch 1 3/8 inch ss nipple $3.03
Shipping $5.35
Total $49.70

Add the cost of the acid and the total is 62.20. Still more than $100 cheaper than buying one ready made.

Replacing the aluminum rod I am using with 3 inches of 1 inch aluminum rod would be about $2.50 in aluminum and eliminate nearly $20 in copper pieces. This also keeps the cost at around the $45 I consider acceptable. It does require the ability to thread the aluminum Rod to fit the Elbow. Another solution woudl be to use 3/4 inch aluminum rod and a 3/4 male thread to 3/4 inch slip adapter. This dos keep a small section of the pipe being copper though. This might be a better solution for that that need parts that just hook together though. I believe something reliable and safe can be found to coat the copper with making it a non issue.

So now I am down to the power supply. I have a battery charger but it is a smart charger that test the battery before starting the charge. it does not recognize a glow plug as a fit battery so it will not send the juice.

The easy answer of course is just yank a battery out of the car and hook up jumper cables. But I am looking at other alternatives as well. One thing that I found that got me thinking was an emergency jump starter kit. I have found several starting at around $40 listed as 300 amps or so. Anyone have any idea if one of these should work?

Otherwise does anyone have a specific battery charger that does work?
 
#76 ·
Big Gun, For one $20 for 3 3/4 inch fittings. I am trying to keep this as low cost as possible. Second somewhere in one of the discussion on OA and vaporizers it was mentioned that the acid reacts with copper and produces a toxic gas. I am trying to avoid copper brass and galvanized steel as much as possible. I am not really sure the amount of gas produced is enough to be concerned with that is why I was willing to make an exception at all. Still the stuff is just way to high priced. Stainless Steel pipe is cheaper.
 
#77 ·
Yup, Stainless is alot cheaper.
Daniel if your lathe is 7x12 why can't you turn a 1 1/4" piece? Hole through the spindle 1"? I can't see what you trying to do but I was curious. I have noticed that alot of battery chargers have the smart charge feature. Don't know about an emergency jump box. You might pick up a core trade in battery from your local parts house that still has some life in it.

Also for everyone, I found some measurements of the cup on the 12v type that slides in the front entrance.
Aluminum block is 1.700 x 1.165 x .360
Cup is machined in the block: 1.170 x 1.050 x .325
Machine the cup tight to one side leaving space for the glow plug.
Block holding glow plug is: .450 x .450 x 1.663
Threads on glow plug are machined off. A set screw in the block holds it in place.
 
#78 ·
Shadow. The capacity of my chuck is only 1 inch diameter. I want to go with a smaller diameter aluminum stock anyway. I just have to wait to get it.

I am thinking of making up a slide it style as well. thanks for the dimensions.
 
#81 ·
Crofter, good info, bad for my design. I will probably have to pre heat the SS and copper fittings on my set up. I do have one idea that I hope will eliminate any travel through pipes yet still use the box on top design. sort of you ideas of a hole in the side of the pipe rather than the end. Only my hole will be in an aluminum rod large enough for a closed end hole and the hot part of the glow plug directly below it. It will have to slide like a drawer through the wall of the box just far enough to be able to add the next dose of acid to the pocket then slide back in to be heated.
 
#82 ·
I re arranged things a bit and now could slip it into a 3/4 high hive entrance. I made an enclosure for the bottom that will keep the glow plugs from being exposed. I said that my plugs would stand up to full battery voltage without burning out; apparently that may only be true when they are tightly screwed into a cylinder head that keeps the body temperature down. I will have to mess with a resistor, or charge in pulses, or perhaps with two glow plugs could hook them in series. Just details. If this wasnt fun and my time free, the 90$ price of the Heilyser Vaporizer would start to look very reasonable! Lol!

A charge of oxalic is only a half teaspoon or a tad more (very scientific) so you dont need a huge heat chamber. If you dont overdrive it, the oxalic is quite calm as it bubbles away; you dont need a lot of freeboard on the sides.
 
#83 ·
lol, yeah I am sure I saw tad listed right in there with ohm. amp and mm somewhere.
Actually I have a tad measuring spoon. a pinch and a scosh as well so keep trying to throw me with those foreign forms of measurement. I am way ahead of you.

I am still looking for a way to power my glow plug. I got hurt yesterday and am not supposed to be walking so it has put a bit of a limp in my progress. I have a bit of an experiment going with melting wax in a 26 lb steel cylinder just setting out in the sun. the cylinder tipped over and landed on one of my toes. the cylinder is just fine. the toe not so much. we spent 12 hours yesterday just trying to get the bleeding to stop. I am minus a toe nail, the entire thing. and got a pretty nasty cut/ tear in the flesh as well. sort of tried to peel the skin off the end of my toe from just behind the nail. Lesson learned don't play with heavy metal objects while barefoot.

Anyway I am confined to a chair until we know the bleeding has stopped so it will slow me down for just a bit. My wife wants me to go to the ER, I am not agreeing just yet. It hurts enough without adding a doctor bill to it.
 
#84 ·
Oh No!' I can feel the throbbing! One thing about it, bee stings now wont amount to mosquito bites by comparison. On the charger; I have some old ones still going without the polarity sensing so you might pick one up at yard sale or Craigs List. Just make sure they are rated for about 15 amp. You can buy a lawn tractor battery for ~30$ and it should be good for at least 5 goes on a charge. Less trouble than stringing cord and charger.
 
#85 ·
Daniel Y,

Don't know how old you are or how your health is. But please don't mess around with significant wounds on your feet. They are notoriously slow to heal and subject to infection. If you wait until you HAVE to go, you could loose a foot, leg, or worse.

Do whatever it takes to get it cleaned, closed, and healed before something bad happens.
 
#89 ·
As you consider a 110V heat source, I wonder if THIS LINK would help to provide a compact heating unit....Can you adapt this tool (designed to apply model airplane coverings)?


Thermostatically controlled up to 350F. View attachment 3063
Looks like it might just work to be converted to a vaporizer.

Daniel, I hope you heal quick. Take good care of yourself.
 
#87 ·
It woudl be very interesting to play around with one of those irons. or any other similar item.
some of several questions that first came to mind where.
How large is it and woudl it fit through the opening of the hive? If not is there enough material to modify it enough to allow it to?

Could the handle be modified or replaced so as to be straight with the plate? if so how difficult would this modification be?

Could the heating element and controller simply be removed and used in a custom made plate?

If one of these where cannibalized just to see what they a re made of . could the individual parts be located at an even lower price?

The idea of a temp control is very desirable even if it is something that is pre set

In addition to making something of this sort work. devices that plug into a cigarette lighter and convert 12v DC to 110 ac do exist

here is just one example. http://www.amazon.com/Universal-110V-Power-Inverter-Adapter/dp/B0015TOTNY

so an AC solution is not that hard to convert to those needing portable 12V DC power supply.
 
#88 ·
Daniel, the iron comes apart and the shoe can easily be replaced. After that, one would have to disassemble it to see what you had. I had one years ago and can't find it this morning. If I find it, I'd be happy to donate to the cause.

From memory, the iron is about three or four inches long and an inch and a half wide. Four screws hold the shoe, you can imagine what would be left without the shoe. :)
 
#94 ·
I forgot that I had one of these irons in the garage. I did take it apart to look at it and may have to talk to a machinist friend. I do have some 1/2" stainless 304 tubing, but I may just finish the one I started with the glow plug. I will be out of town this weekend but may finish Sunday. My only concern with it is that the OA will be directly on the glow plug.
 
#95 ·
There is an incredible variety of ideas appearing concerning these devices. Once some of them have been tried out I would really like to see a single thread or something in the way of an article made up of them. The way it is going it could be quite a project.

By the way, thanks all for the concern. The damage to my toes does not seem to be as bad as I first feared. I guess that might explain why I was not in as much pain as I first thought I should be. In all it did take nearly 60 hours to completely stop the bleeding, yet I was not really feeling any pain. It was confusing. We then focused on the possible causes my blood may not be clotting. One problem we found would have been a calcium and Vitamin K2 deficiency. I took supplements of both and the bleeding stopped within 2 hours. I am now taking daily doses of calcium, K2 and D3. I guess they all work together. the K2 and D3 are required for my Body to even use the calcium. I have had noticeable improvement of the toe for the past two days.

Again thanks for the concern and I just wanted to let you all know that it seems to be fine. I should be ready to go out and smash another one soon.

I am waiting for my OA to arrive still so I have not been able to test my design. So of the comments about the vapor condensating on the pipe has me concerned. But here are a few of my thoughts.

In the article at scientific beekeeping it is mentioned that a dose is 1.5 to 3 grams. (I believe grams is the unit of measure I do know the numbers are correct). It goes on to say that no measured improvement of mite kill was noticed with the higher dose. It appears that the most effective results are already reached with just 1.5 grams per box although a higher dose does not appear to be harmful. So if you are using the higher dosage there is room to loose up to half the acid to condensation etc and still effectively treat the hive.

I am using a 3/8 inch copper cap as my measuring spoon where one cap full will be one dose for a box. Unless I am mistaken those caps are approx 3 grams.

I am in hopes my acid arrives today as I really hope to get my hives treated soon.

More concern on the info I have found concerning treatment.

According to the most recent information I have been seeing it seems that multiple treatments (3 to 4) spaced a week to ten days apart is currently the common wisdom. In the article at SB (scientific beekeeping) He recommends only one treatment per year with some reference that more frequent treatments may be harmful to the bees. I do realize that the SB info is older and may not have been updated with more recent understanding of OA.
 
#96 ·
According to the most recent information I have been seeing it seems that multiple treatments (3 to 4) spaced a week to ten days apart is currently the common wisdom. In the article at SB (scientific beekeeping) He recommends only one treatment per year with some reference that more frequent treatments may be harmful to the bees. I do realize that the SB info is older and may not have been updated with more recent understanding of OA.
I've read the same thing. I believe the SB article was referring to treating by trickle once a year. You can supposedly treat by vapor as often as needed.
 
#97 ·
I got my replacement glo plugs and decided I did not want them glowing that bright yellow. Since I am using two plugs straddling the dish I have a bit of heat to spare. 16" of stainless wire as a resistor takes them down to cherry red. I insulated the bottom and sides of my bowl to keep the heat in and reduce flame hazard in the hive. Probably would still be a good idea to rake the ladder comb off the bottom of the frames where you shove the vaporizer in. I have to try some measured charges and time the heat cycle. It takes close to a minute to start vapor but then there is a fair bit of coast with stored heat to finish boil off.
 
#98 · (Edited)
Couple of pictures. The chamber is about 1 1/2" long, 3/4" high and wide. Overall about 7/8" high and 1 1/2" wide. The cladding is aluminum with glass cloth surrounding chamber. Near the end of boil you can see the condensed whiskers of oxalic that hit the cold spots. There probably is not a whole lot of mass to it though. There is no residue on any parts that got up to temperature. It looks like it will take two minutes of current on and three minutes start till all the crystal has evaporated. My feeling is you will probably want to keep the weight as low as possible and the area small that you are heating. This is just proof of concept so no concessions to making it purty yet. No use putting on lipstick if it is still a pig!
 

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#99 ·
"Add the cost of the acid and the total is 62.20. Still more than $100 cheaper than buying one ready made."
Daniel Y,

Check out these folks, http://www.members.shaw.ca/orioleln/index.html , they make & sell a 12 volt OA vaporizer for $ 90.00 plus s/h. They are out of Canada. Have not bought one yet, but I hear they are good folks to deal with. Just my 2 cents. :)

BTW, new to this forum, thanks for having me.
 
#105 ·
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