Forge problems.

C

chriswillman

Joined
May 1, 2011
Messages
24
Hey guys, I just made a forge from a stove pipe with 1/2 inch thick insawool around the inside. I ordered it as 1 inch thick but the tube would seem clogged if I put so much in. So it started out 24 inches long, and I had one mapp gas burner and one end sealed with the insawool. I cut it in half this morning, so I have a 12 inch tube with 1/2 thick insawool around the inside, with a pretty bad job of a satanite coating on the inside. I have been trying to use 1 Mapp gas torch as a burner, I just stick the whole head of the torch in there and the flame is inside the pipe itself. When reading stuff about these gas forged a while ago, I remember something about how far away the torch needs to be. I can't seem to get my steel hot enough. Even if I plug up the ends with insawool. Should I need another torch? The tube is 12 inches long, and the diameter inside the insawool is only 3 and a half inches. How long should it take the forge to heat up? How far away should the burner be?
 
Sounds like your forge chamber may still be too big for your torch. Also, 1/2" of wool is just not much at all. I'd recommend 1" at least, and 2" is way better. Maybe upgrade to 6" stovepipe with two layers of that 1/2" wool.

I'd say you want your torch head positioned so that the tip is just barely into the inswool, not into the wool far at all. It'll likely overheat if pushed in farther. Try sealing around the torch tip with more wool scraps, so air can't get past. Block the front door up a little with firebrick or even steel with wool.

I've not personally built a torch-type forge, so others may have better tips.
 
One half inch of wool is not enough to hold the heat you are producing with the torch. If you seal up one end of the forge body there is no way to regulate the oxygen inside the tube. Not trying to blunt your experimental nature but there is reason many people end up building a proven forge unit. I didn't; but there is a reason.:confused:

Small changes in a small forge can result in big changes in operation.

Good luck, Fred
 
Aside from you not having enough insulation, I also wonder if the burner you are using is too small. Is it one of the small plumber soldering torches? If so, I would think it is one problem. I have a 1" burner on my blown burner and it works great because it is so big.
 
I built a forge out of a stovepipe using 1.5 inch of refractory cement and a venturi burner with propane. Previous to that I made a small coffee can forge with 3/4 inch thick cement and used a regular torch head with mapp gas. There would have been no way to get enough heat in the stovepipe just using the torch. I recommend either putting in more inswool, using a bigger torch (weed burner, venturi or blown burner) or using your existing torch with a smaller forge. What you are doing with it will determine what you should do. If you are forging, get a bigger burner and put in more inswool, if just heat treating 1 or 2 knives, make a smaller forge (coffee can style). However, you will eventually want a bigger forge anyway so I recommend buying or making a bigger burner and put at least another layer of wool in your forge. There are a couple schools of thought on the lining itself as well. Some say 1" layer is best, others that 2" is best. No matter what, you need at least 1" for a forge that size. Either way, I believe pictures are in order.
 
http://zoellerforge.com/simplegasforge.html

http://www.woodsmonkey.com/index.ph...mini-forge&catid=41:how-to-articles&Itemid=63

Check out these links and search for forges here. People have built all kinds and it's all there . Did you put anything on the ceramic wool? You should make it thicker and coat it with satanite. Keep your torch tip at least 1/2" from the entry hole , you dont want to get it too hot bad stuff can happen. I have been messing around with my mini forge for the past 2 weeks and reading up on them there is all the info in those links and here if you look. There is a WIP forge build thread started a day or two ago you could look at or the other forge build question thread on the main page or second.
 
Thank you all so much. I added more insawool, and am trying to rig the the torch a bit further away. I just heat treated my first 1084 knife. It's looking good so far. Did 2 hour temper in the oven at 350.
 
You must log in or register to reply here.
Back
Top