emtor Posted April 20 Share Posted April 20 Up until today I've been heat treating knife blanks in a simple charcoal forge. It's not easy to keep the temperature steady and even harder to keep the tip of the blade at the same temp as the rest of the blade. One trick is to place a piece of steel tubing inside the forge and place the knife blank into that to get a more even temp, but even this doesn't seem to help much since the tip always seems to get way to hot. So, I made a propane forge from a can lined with 2 inches of ceramic fibre blanket treated with waterglass and a thin layer of refractory. The burner is just the burner that came with my propane tank and the 2 bar adjustable pressure regulator. Rumour has it that its hard to keep a knife blank steady at the desired temp inside a propane forge. Today I tested with a piece of steel tubing inside the forge. After ten minutes the steel tubing was glowing along its full length with a color indicating about 800 deg.C (1472F). Then I inserted the knife blank (1095) and adjusted the gas flow till the knife got to non-magnetic and then some, and then I let it soak for five minutes. The blade was at a very even temp along its entire length including the very tip. Quenched in oil and tested with a file. File skated across the edge and then I broke off the tip and examined the grain structure. The knife blank was glass hard and the grain structure was very even and fine which indicates the temp was high enough to harden the steel but not so high as to cause grain growth. So, yes,-it's seems to be possible to control the temp in a propane forge within reasonable limits. Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.