Coal vs propane vs charcoal for a hobby forge

Propane: clean, consistent, easy to light, works in a suburb without complaints. Needs a well-built forge and good ventilation (carbon monoxide). Hardest to get welding heat on a cheap burner.

Coal (bituminous): hottest, best for forge welding, cheap per heat. Smoky when lighting, needs a firepot and blower, neighbors notice, harder to find.

Lump charcoal: the old-school fuel. Clean-burning, easy to find at any grocery store, gets plenty hot, but you burn through it fast and the sparks are a fire hazard. Great for a first forge made from a brake drum.

Most hobbyists end up with propane for daily work and a coal or charcoal fire for welding and big stock.