#30 Forced Air Furnace
This is my most recent furnace. It takes up to a #30 crucible, 90 lb. of bronze or 30 lb. of aluminum. The forced air propane burner just uses a rabbit cage blower and so is not very loud (in consideration of my neighbors). The construction of this furnace is similar to the Helium Tank Furnace - castable bottom and top with ceramic fiber sides. The ceramic fiber is painted with a zircon flour/colloidal silica mix which protects the fiber from abrasion.
Update: I've finally had a chance do a larger melt with this baby a couple of weeks ago - it works great! Not very loud, melted 45 lbs of bronze in under 30 minutes. The zircon/colloidal mix on the walls does a nice job of heat reflection. The only problem was that it froze up the 40 lb propane tank in under 10 minutes - I had to put the tank in a bucket of water, which kept it warm enough to hold the pressure. Since the melt, I purchased another 40 lb tank and I'll hook up the regulator to both. It was a two man pour, my friend Jim helped out as the deadman. It was a lot of fun; I'm still working on the sculpture (I'm chasing the part I poured the other week and I have to make and pour one or two more sections), when I post it in the Bronze Gallery I'll put a link here.