As a few of you know, I’ve been working a lot on ideas and forge designs, and have built three or four so far. The biggest obstacle so far has been getting enough heat, but to keep that heat IN the forge, not on the wood around it. I’ve built a coal forge, stacked around bricks with a propane torch at an angle, housed stacked bricks in a steel barrel, and finally a forge made from an old soup can.
After having to dismantle the barrel forge because of fire risks, I did research to find a better way of containing the heat. My research turned up this video, https://www.youtube.com/watch?v=jBVa2bw3r_k , and so I began building according to the general how-to shown in the video, with a few tweaks of my own.
I found an old soup can in the garage, and, after drilling holes through the side, attached it to two steel L-strips. I then mixed a 50-50 mixture of plaster of paris and sand (the sand keeps the plaster from cracking under the heat), smoothed it out onto the inside of the can, narrowing the cavity at the two ends. I then drilled a hole at the top so I could insert the tip of a propane torch, and drilled the L-strips to the end of the workbench, where I put several pieces of tile to shield the wood from the heat. The first firing-up of the forge dried out the plaster, so I didn’t have to wait for it to dry. I hate waiting.
All I have to do to fire it up is insert the tip of the torch into the hole at the top, and light the propane. The heat is conserved in the small cavity, and I usually stack firebricks around the holes to keep even more heat in. This thing really gets hot!