Casting Aluminum w/ Homemade Furnace 

Here I am casting a part for a Crayford Style Focuser to be used with a 8" Newtonian telescope I'm building. I'm using a propane furnace, a graphite crucible, and the "mold" is a tin soup can. I need a stock of aluminum about 3" in dia. Before you say it, I know it is not safe to cast metal with flip-flops and shorts, but it's the middle of summer in Phoenix here... All parts will be machined on the mini lathe and mini mill.