I've been thinking of buying a pre-made forge online, but then after reading through the forge building stickies here, I decided to build my own. Hobby-level use consisting of some blacksmith tool manufacturing (tongs, punches, etc.), some hunting/kitchen knives, and some metal artwork. Some day I'd like to try my hand at damascus billet, but that will likely be down the road.
I drew up some plans based on what I read here, and some preferences I had. Fuel source will be propane, and I plan to build a forced-air ribbon burner. See attached picture which shows a cross-section view. I'm still in the early design stages, and am giving the doors some thought...
I'm thinking of splitting the body in half (clam-shell design) to make it easier to apply castable refractory, and to make future maintenance easier. 2 layers of 1" insulating thermal wool, each layer rigidized. Inside covered in a 1/2" layer of castable refractory. Floor will have 1" of castable refractory with a high alumina kiln shelf sitting on the floor. Tapered ribbon burner at TDC of body (I'm open to suggestions on placement - just at the drawing stage at this point.) Inside clearance at widest point will be 7". Clearance from ribbon burner to floor seems to be coming in at 6" (assuming a 1/2" shelf thickness). The plans are calling for an 8" long burner, but to be honest, I just made that number up. If I use a propane tank as the body, the floor of the forge may only be about 9" long, so that burner length would be overkill. If I get some steel pipe from the local scrap metal business, I can make the forge floor longer (12"?) and an 8" burner may make more sense. But then I might be making a forge that is much larger/longer than I need it to be for my uses...
Some questions:
For forges made from 20lb. propane bottles, how deep is the usable floor space in the forge? (9"?)
How long should the ribbon burner be compared to the forge's depth?
Where can I find high alumina kiln shelf that is only 5"-6" wide? Most places online seem to sell them in 10.5" and wider. Can they be cut?
I plan to support members on this site by purchasing my insulating materials here. If someone offers kiln shelf, let me me know! The pages here seem to only sell refractory, wool, rigidizer, coatings, etc.
Any feedback/suggestions on my design are much appreciated!
Thanks,
Matt