Hello everyone!
I just finished doing the test fire of my charcoal forge. So far it seems to work. Wooden box isnt burning, the bottom of the box isnt heating up at all it seems and it can get a piece of steel to a decent color.
As for the forge itself it's a 2 foot by 2 foot box about 8 inches deep. Theres a 3/4th inch pipe with 3 1/8th holes drilled to provide air. I plan on getting some firebrick to help make the fire a bit deeper and not as wide. Currently using a shop vac to blow in air with a piece of duct tape over the pipe to try and prevent to much air from getting in. The dirt is about 40ish pounds of clay, 100 pounds of sand, and around 50 pounds of pottery clay. I'm actually surprised the box didnt collapse.
Only problems I'm having is trying to get to welding heat at the moment. I suspect it's not deep enough right now so I'm thinking of narrowing the pit to try and make it so stacking hire requires less charcoal. I also plan on breaking up the charcoal even more, I think the large chunks are disrupting the fuel from insulating heat inside.
And yes I know I'm not supposed to stick a piece of metal into the fire like that.
Pictures of my test fire. I'll add pictures of what the pot looks like after the fuel burns itself out.