Easy foundry forge??? With this basic design you can melt lead in minutes and get steel hot enough for the anvil in no time. Add some refactory and let me know what your results are!
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Step 1: Fire Extinguisher Foundry or Is It a Forge?
Bear with me while I stumble through my first instructible. My original intent was to simply melt down and clean up range lead to cast into muffins to use at a later date for bullet casting. I didn't need to worry about hardness (BHS) as range lead is just about the most perfect alloy you can use to cast bullets for lower velocity handgun calibers. I had 100's of pounds of lead to work with as a result of an indoor range clean out that produced tonnage so a hot plate just wasn't going to cut it. So.... select a suitable fire extinguisher from the extinguisher storage area. these are all heavy steel with no lite weights or aluminum in the pile. The pictures above show the results of using it as a foundry as well as demonstrate how hot this gets. That's a piece of hard steel left in the fire to long and it's amazing how the flames will devour an HC railroad spike.
Step 2: Assemble Your Components.
For starters you will need.
1) Suitable fire extinguisher.
2) Drill and a sharp bit. I used 1/4 inch.
3) Angle grinder with both cut off and grinding blades.
4) One inch pipe. Use your imagination just don't use galvanized. I went with a T- Connection, a couple of nipples and end caps and a few straight pieces.
5) A source of air like a hair dryer, Shop Vac, bathroom fan or in my case an air compressor.
6) miscellaneous doodads that I can't remember or that you can figure out. In all likelihood improving over my design.
Step 3: As Simple As You Wish.
The easiest method by far is where I started and is more than sufficient to play around with railroad spikes. Cut your extinguisher down to your desired height. I've found that 8 inches is a good height that does the job but doesn't require a full bag of coal.
Screw a 2 inch nipple into the inside of your vessel. Drill a whole bunch of holes thru an end cap and thread it onto your interior nipple. configure your exterior pipe any way you wish finishing with another end cap.
Step 4: The Business End of Things.
This is what makes this thing scary. I was making a move on my daughter's hair dryer when she cut me off at the pass. I needed an alternative and that came in the former of my air compressor. I drilled a hole thru the end cap to accommodate a 1/4 inch compressor fittiting. In the picture above you'll note that I welded the fitting in place. in my first build I just snuggled the fitting into the end cap with a nut on either side. I lost some air but there was plenty to go around. I added a ball valve to control air flow and a quick connect because I had one.
Step 5: Full Potential Not Yet Reached.
I'm using 2 inch black anthracite coal because that's all I could find. I couldn't find blacksmithing coal but I don't know the difference so nothing lost. I hooked up to 100 PSI of air and started my fire. Initially the 2 inch coal was tough to get burning but once it did I nudged the air flow up. Boy did it take off then. With a full belly of coal and all the air I could supply she sounds and looks like a jet engine and is hotter than a pistol and will singe your facial hair off at 20 feet. No need for a tanning booth that's for sure.
Step 6: As a Lead Melter...
If I'm melting lead I allow no company. I can put 50 pounds of junk lead on the flame and retire to the house to watch from a window. You don't want to be anywhere close to the belching flames and noxious smoke. After 15 minutes I stir the dross in the pot with a large steel paddle and all the odd bits of brass and steel float to the top. A long heavy handled slotted spoon work well to remove the dross. When most of the dross has been removed a chunk of candle and some sawdust is stirred in to act as a flux and it certainly brings all the impurities to the surface to be removed. The clean lead is then carefully ladled into muffin pans. The old timers called the molten lead the silver devil and it will burn through the top of your boot before you can scream.
Step 7: As a Forge...
I really haven't yet started to pound on steel but it's clearly hot enough without any refactory materials or secondary vessel. I don't know how hot I could get it if I was to properly insulate the extinguisher. I do know that as it stands I have to be careful not to get my steel to hot. I can put a file in the pot and come back in 10 minutes to find a sparkling disintegrating mess. it doesn't make sense to a simpleton like myself that I can say I can melt a file.
All I can say is be careful. only a fool would not use every safety tool available to them for every step of this build. Eye protection and mask as well as heavy gloves at every stage. If the flying metal from the grinding doesn't get you the heat will. consider EVERYTHING you pick up to be so hot it will cook you. Be afraid... Be very afraid.