I'm working on building a furnace. I've been reading and collecting parts and thought I might run it by an experienced group before I start building to make sure I'm not missing something. Parts... 6 gallon galvanized garbage can with lid https://www.homedepot.com/p/Behrens...nd-Trash-Can-with-Locking-Lid-00108/202264761 2" thick ceramic wool insulation fumed silica for ridgidizer Ebay T burner High pressure regulator and hose Kast-o-lite 30 Metrikote I'm planning on lining the can with the wool, with a firebrick on the bottom for supporting the crucible. Ridgidize the wool and fire it when the water dries. Then line with the kast-o-lite and let it cure. It sounds like I should bag it with a water container for 24 hours to cure, then let it slowly dry out. Once that's fired, the Metrikote in a thin layer, dry and fire. It looks like some people here have used sonotube to support the refractory while it cures. That would be nice as I could cast the walls in one go without worrying that it would sag. I'm not sure how people are physically supporting the burner tube. Putting a piece of tube/pipe in the refractory before casting it makes sense, but that just gets you a hole in the side. I suppose you could just place the burner in there and the flame will generally be forced into the furnace chamber. For supporting the refractory in the lid, I've seen mention of using threaded rod and nuts to act as a support. If I do that along with the same process for the walls, would that work well? For exhaust, I was thinking of a 3 inch hole in the lid. I haven't decided if it should be attached. It seems like the hot lid would be a potential danger so having it on a hinge of some sort might be a good idea. I like the idea of one that pivots horizontally rather than flipping up.
Cast a bit of pipe/tube in the side bigger than your burner. Put a few (3) bolts through it to support the burner in a y pattern. If you have or are worried about flames coming out the back of the tube. Pack a little ceramic wool in around the burner.
