Author Topic: small gunmaker's forge  (Read 3054 times)

Offline Clint

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small gunmaker's forge
« on: January 02, 2021, 01:54:05 AM »
I have been threatening to write up some pages about spring making but as a prelude to the springs I thought it would be handy to show an easy to make forge. This is what I came up with,. The forge is big enough to heat most rifle parts and compact enough to hide under the bench when you don't need it.

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I wanted to make this from a 20 lb propane tank, but didn't want to get into a big discussion about safety. We are using a worn out air compressor here and almost any steel box or container will work. The openings were made with a hand held angle grinder with cutoff wheels. If you know someone with a plasma cutter or a set of torches, this work would go very easily. The fan is an old computer thing and it provides plenty of air. Read the labling on the fan to determine the voltage req.

 [url=https://ibb.co/c1Mc2yK]

I left 'flaps' over and under the fan to support it and to keep excess ash etc from getting into the fan. For me, the most difficult part of this project was finding an iron pot. I had a couple of iron casserole type pans that might work, but none of them really fit the compessor tank.
 A customer who had used some iron pots as planters, gave me one and it fit the bill. I drilled six 3/8" holes around the bottom of the pot for air and fitted the pot into the top of the tank.

 


 
You will have to experiment with hole size and placement to tune the forge, basically, if a lot of air is blowing back around the fan, more holes can be added. I tried this forge out with coked coal, but i think it will burn better with charcoal. This is an open LIVE fire and although I feel that it is safe to use it will generate a lot of carbon monoxide and might "set your pants on fire" if you don't use your head. Having said that, the forge is quiet, hot and very controllable.
C W

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Offline rich pierce

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Re: small gunmaker's forge
« Reply #1 on: January 02, 2021, 02:08:46 AM »
Nice! Diameter of the iron pot?
Andover, Vermont

Offline Clint

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Re: small gunmaker's forge
« Reply #2 on: January 02, 2021, 04:51:23 AM »
The size of the pot should be 5 -8" in diameter, that would give enough room to anneal a butt plate. The depth of the pot is very important. Four inches is a good depth. Forced air fires will oxidize metals and we want a fire deep enough to consume as much oxogen as possible. The metal should be kept near the top of the fire and covered with a little charcoal. The deeper into the fire, the more oxogen. It is surprising how little air is needed to get a hot fire, note the ragged fit around the fan.

Offline flatsguide

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Re: small gunmaker's forge
« Reply #3 on: January 03, 2021, 07:09:53 AM »
Neat! Compact and sure is economical.
Cheers Richard