March 24, 200719 yr Hello. I sometimes have need of heating long lengths of barstock for projects (straightening blades or bars and heat treating), but my fire pot is only about 5 inches in diameter. I have heard about using a cave fire to do this, but I am unsure how, exactly. If someone could explain, that'd be great. Thanks! Archie
March 24, 200719 yr Remember, when forming the cave, form it diagonal to the suqare corners of the firepot, that will give you a longer cave.
March 24, 200719 yr ApprenticeMan, a 5" Dia firepot won't have corners. hehe But you are right about running diagonal with a square firepot.
March 24, 200719 yr If you make a nice, big beehive fire, and then poke a hole not only in front but in the back also, the resulting cave will allow you to heat a section more efficiently than a trough. Still, it will only heat a section at a time. Heat part, move it and heat the next section, etc. The parts you heated first will cool, but will still be hot, and eventually by moving the piece back and forth through your cave you'll get a (reasonably) even heat.
March 24, 200719 yr Or for the rare need of a long fire you can dig a trench forge in the yard. Thomas
March 24, 200719 yr ive been putting a length of 3 inch box section in the fire and building the fire up around that.it gets a nice even heat and you can heat treat inside it ,and see whats going on easily.another bonus is you dont get much scale build up. hope it helps.
March 24, 200719 yr ApprenticeMan, a 5" Dia firepot won't have corners. hehe But you are right about running diagonal with a square firepot. Oh yeah, misread:p
March 25, 200719 yr When hammering by hand, how long a heat zone can you work before it cools naturally? I see no reason to heat 24" of length so you can work a 6" section of material. On a power hammer you do need a much longer heat zone as the machine does more work per foot while the material is still hot. I think it would help to redefine the problem with real numbers. What do you want to accomplish using what size fire. What tools are you using (hand hammer, power hammer, striker, etc).
March 25, 200719 yr This is one of the reasons a side blast tuyere sometimes is better than a bottom blast - you can place a fire brick in front of the pipe and force the air to divert both ways and eventually get a fire that can be 15-20 inches long. You could also try 4 fire bricks - two on each side, end to end. You build a fire in the trough and the bricks help keep it from spreading. In the absence of bricks, water is your best bet to get the fire to channel.
March 25, 200719 yr Glenn, I'm gonna play devils advocate with this one. Needs vary. I built a plant hanger for a fella one time from his drawing. Scrolled hanger ( sorry no pics) with a 90
March 25, 200719 yr I made a tool rack for a portable forge with that forge. It had a 4" square firepot. I heated a piece of 3/8 rd and hammmered flat then twisted. I wanted to do the twist all at one time, so I ran th bar back and forth through the fire til I had about 20" at a high orange. It takes time and lots of patience. After that I understand the value of working smaller sections and being consistent from one section to the next. it is faster too.
March 25, 200719 yr Author What I've been working on three scrolls for a small table-like stand, and also a long integral bolster knife. For the scrolls, I only know the way of making the scroll curly of heating up a long section and then knocking it to a right angle to the rest of the bar and then knocking it into a curly shape, so being able to heat a long length would be useful. And for the blades, I am having trouble straighting them using only small heated sections. Thanks for the help everyone! Archie
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.