I got such a great response from the Easy Dual Fuel Furnace Burner
that it only made sense to follow it up with the rest of the furnace.
This furnace will be able to handle melting aluminum and bronze with no trouble. In theory it should be able to melt iron too but that's probably pushing it.
I've been using my furnace for a couple years now and it has worked out quite well. My design is based on information I picked up from the backyard metalcasting forum
. It's a great resource and community. There are a bunch of furnace builds there exploring a variety of ideas. I recommend checking it out. I'd also read this comprehensive guide
for a general overview of metal casting and furnace design.