Heating Long Lengths in a Coal Forge

[stuarthesmith]

In the shop where I used to work, we used to make a lot of chain links. One type of link we made was round links, two inches in diameter. To make these, we used to heat up lengths of round stock, and then bend them around a pipe two inches in diameter, wrapping the hot steel around the pipe like a coil, then cutting it later into links. To do this the most quickly, we used to heat the steel about two and a half feet at a time, in our coal forges. How does one do that, when the firepot is only about a foot long? By heating an area over the fire pot, then, when that area gets orange hot, sliding the steel forward until another 8 inches or so gets hot, then pulling it back until the opposite end of the stock gets red hot, then sliding the steel in and out of the fire, reheating the different areas of the bar in intervals of about twenty seconds or so, until a long length of the steel gets yellow-hot by sliding the steel in and out of the fire. This greatly increases the amount of steel you can bend in one heat. Other applications for this method will help smiths heat up longer lengths of steel at one time.

[pkrankow]

I understand that some sword makers use this technique for the heat treat process, but not such a high heat.

BTW it works in a gas forge too, I can heat about 36 inches to bright red in my forge, 18 inches to a yellow. My 1 burner propane forge is only about 9 inches long.

I have only done this only a few times and the heat was adequately even for the tasks I was doing, but requires practice if the task requires even heat.

Phil

[Rich Hale]

Interesting Phil do you have any pictures of things yoiu have made using this process?

[pkrankow]

Interesting Phil do you have any pictures of things yoiu have made using this process?

I bent some 1 inch pipe almost 1/4 the way around a rim for making some table legs sorta like on older rivet forges. I took a different tack and the bent pipes are buried in a corner under other junk and garden tools. The uneven heating caused the pipe to partially collapse some in a few places.

In several tries I got some rather long lengths heated, took a bit of experimentation since I had never tried heating that long of a section before. I heated the fist section more than once to see how it worked.

I made 3 bent sections for legs, but as I said, I didn't use them. I ran into several learning curves and dropped the idea. I was trying to make a table similar to a rivet forge, and ended up bolting a piece of sheet metal to a set of legs from a folding work table. (that is posted in "show me your forge, solid fuel)

I did about 18 inches making a candle holder that I wrapped up around a mandrel. The project broke before as I was wrapping though. I have not had a chance to try again.

Phil

[ThomasPowers]

I had to box fold some 3/8" plate once to make a fire box for the Santa Maria.

I dug a trench in the back yard and put a piece of pipe with a lot of holes drilled through it down the center for a tuyere and used a vacuum to blow it. Cost $0 and I was able to get several feet hot enough to bend over a chunk of RR rail clamped to two uprights about 4 feet apart.

[CurlyGeorge]

Hey Stuart. Thanks for the idea of making chin links like that. I do a lot of chain demos and that would work great to have a bunch rounded and cut ahead of time. Take a welding heat and then reshape to long links. Great idea. Thanks again. :D