# Oxalic Acid vaporizer; black iron pipe?



## mhorowit (Sep 25, 2011)

I'd like to build an oxalic acid vaporizer and I'd like to build it using black iron pipe. I'd apply heat from a torch. Anyone know of any problems with that approach? - Mike


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## Ozone (May 24, 2011)

Having not tried this, but I can guess at some problems.

One, the size of the pipe and where you plan to insert it
Two, the OA melts and then vaporizes, and then seems to re-melt when it contacts the cool pipe on its way out the 'exit'
three, the general mass of the pipe that you would have to heat
four, the longer the process takes, the more bee congestion that occurs at the entrance

Just some thoughts


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## Wimmels (Jul 16, 2012)

The simple Oxalic acid vaporizers I have seen over here were all made from copper plumbing tube.

There are several reasons why copper is used, its more resistant to the acid and it carries the heat better. If you heat up one side of the iron pipe its not said that the other side of the pipe has the same temperature causing the Acid to condense again.

If I were you I would stay with copper.


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## mhorowit (Sep 25, 2011)

Wimmels said:


> The simple Oxalic acid vaporizers I have seen over here were all made from copper plumbing tube.
> 
> There are several reasons why copper is used, its more resistant to the acid and it carries the heat better. If you heat up one side of the iron pipe its not said that the other side of the pipe has the same temperature causing the Acid to condense again.
> 
> If I were you I would stay with copper.


Good reasoning - Mike


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## WWW (Feb 6, 2011)

Indeed, tubing is preferable to pipe which takes longer to heat up and longer to cool down unless it is dunked in a bucket of water, then as mentioned above there is the possible problem of re-crystallization in the delivery section. Heat is a lot easier to control with tubing. My vaporizer is made of stainless steel tubing with a reservoir for the OA, copper works just as well.


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## danno (Dec 17, 2007)

I guarantee you will get a whiff of the vapors being this close. Even if you use the wind a slight change in direction will happen. The only ways around this is to spend the money on a respirator with acid cartridges or spend the money and buy a 12 volt with a long cord. I use the 12 volt and still get a whiff now and then. Alittle wont kill ya but you will know the instant it happens


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## crofter (May 5, 2011)

Re solidifying *wil*l be a problem. It is hard to estimate how much of your measured charge actually went into the hive. The less mass of the delivery pipe the better and also very important is its heat conductivity. The higher it is the easier to get heat to flow into the delivery end of the pipe. Stainless tubing wins points on being thinner so less mass but its heat conductivity is even worse than plain carbon steel and much, much less than copper. I have made 4 different ones. The ones you heat with a torch tends to have you down close to the hive front; not good. The electric ones heated with the glow plugs is the easiest to control from a distance and puts the heat and OA entirely inside the hive and you can be 20 feet away. I made several from stainless and the heat conductivity creates problems to get a good clean vaporization without overheating part of the process which is a caution. The last one is a keeper and is made of aluminum and has a pair of glow plugs. One minute from power on till vapour starts and power off at two minutes. Vapor continues for another thirty seconds. No camera at present!


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## WWW (Feb 6, 2011)

I inject the OA via the stainless tube on top of the sealed hives where I can watch the vaporization under a plexiglass cover, I have not had any problems but the temperature has to be controlled precisely, just a little too much heat with the torch and the OA will flash off into harmless co2 and water vapor, too little heat and the OA will recrystallize in the delivery tube. The person doing this procedure must know how to finesse the torch in order to get the correct results, with a little practice however and done correctly the resulting mite kill is very thorough. Because of the need for precise heat control it is best to use this method in a way in which you can see the vapor being formed, and that would be tough to do at the entrance of a hive.

An electric unit such as what crofter is describing is much quicker and easier to use, it also allows a person to place it into the entrance of a hive and step back away to operate it so it's a bit safer as well. There are several companies which sell these units for those who do not have the equipment or ability to build their own .


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