Spent Sat and Sun working on finishing off the can pile.
After a 30-40gal trashcan of crushed cans, and a fair amount of uncrushed cans... I have around 18lb of aluminum ingots.
Some home made crucible tongs worked out nicely. Two 1/8" x 1" x 36" weldable flat boars from hardware store. Two bits of 1 or 1-1/8" angle iron about 1" long each. Some 1/4 or 3/16 (i forget) round stock (also weldable), and an 1" x 18" black iron pipe cut in half to act as handles.
Q & A:
Q) Was working with cans worth it ?
A) Not really.
It's slow to fill the pot - costing you money in fuel and trying your patience.
It produces a lot of waste.
The alloy that makes up cans (ABC or something... american beverage can ?) is not great for casting other things.
Because of trying to gently push cans down into the molten metal / crucible, you're also putting un-needed pressure on the crucible.
Q) Charcoal or propane ?
A) For me, propane.
Charcoal was interesting for seeing what I thought of the process, but propane is just cleaner and less fuss. It's also cheaper, I think.
Building the burner will take a tiny amount of time, or buying a burner will add a bit of cost - but if you're gonna play with this, might as well just accept these things.
Being able to simply start the furnace and not have to play with charcoal management is a huge benefit. Also not dealing with charcoal dust is really nice.
I dunno if forced air charcoal can be made to run hotter or not. Waste oil burners are a valid 'thing' for running hotter, though.
Q) Opinions on the cheap burner made from hardware store stuff ?
A) Works fine for me. During actual melts I've had no blow outs or any other issues. I dunno if some flaps for chokes would be of benefit or not.
Q) Bought crucible or home made ?
A) For me, bought.
Food cans really didn't work out well when melting pop cans. With chunkier source material, it might do okay... I dunno.
Propane bottles really seemed like they wanted to work, but I never had any luck. Again, using better source metal (not cans) might make them far more viable for a few melts. The whole 'press the can down into the pool' really seems to hurt things.
Exhaust pipe did somewhat okay... but not terribly great either. Again - better source material might make all the difference...
Notice a pattern of not liking cans ?
Never tried a fire extinguisher.
Never got to try some 1/4" wall pipe or other thick pipe stuff.
I had bought a 'salamander' A shaped crucible. Fabricated up some lifting tongs. I'm really happy with it. 3 or 4 melts with no problems what so ever.
Q) Thoughts on the furnace
A) I approve. It's inexpensive, fun to do/learn-to-do, and works. And relatively inexpensive. Make your own!
A more round burn chamber would be nice heh. A slightly larger burn chamber would also be nice to better fit the crucible I have (squeezing the lifting tongs in it is a chore).
I would possibly suggest some kind of more / better re-enforcement inside of it. I have plenty of screws sticking in from the handles and seems - which the furnace body seems generally okay. The lid, however, does have a crack or two in it that makes me 'hmmmm' to myself.
