Also, you can melt aluminum in practically any furnace composition that will stand the heat -- a woodstove for example with hot embers in it, a hole in the ground, a woodfire, loose or bound bricks, a steel box or barrel, etc. People make a big deal out of it, and that can be fun, buying expensive stuff, and doing high tech things, but if you don't have money or access, you can still melt ALU.