I recently decided that I would try my hand at metal casting as a way to recycle aluminum cans. After doing some research, check out http://www.backyardmetalcasting.com/
I found out the easiest way to get started would be melt some cans and pour them into a cup cake pan to make ingots. I can remelt them later once I figure out what I want to cast and get some more experience melting the cans down.
After looking at some of the furnaces here on Instructables I decided to make a decent crucible, the cup the metal melts in, and furnace from a paint can. I made the crucible from 3"OD x 1/4"thick steel tube with 1/4" steel plate on the bottom. I also made a special hooked handle to lift the crucible out of the furnace and and another hooked rod to pour the liquid aluminum out. I welded all of these parts together. For the furnace I just used a whole saw to put a hole in the lower side in the paint can. I used another steel tube, placed in the hole, as the blower tube. I bought a $10 hair dryer for a blower.
The basic idea is to put the crucible in the paint can and then fill the can with charcoal. Light the charcoal and let it get going, then turn on the blower to get things nice and hot. I used a paint can lid with seven 1/4" holes drilled in the top to keep the heat in the paint can while the crucible heats up. I also found that burying the can in the ground really helps to keep the heat in. The crucible needs to get red hot, which took about 15 min and a few charcoal reloads. Then start putting the cans in the crucible, about three at a time. Let them melt and then clean out the slag in the crucible. Slag is all the unwanted oxidized metal and ink used on the cans. I used a 1"x 1/8" piece of steel about 3ft long to get the slag out. Aluminum cans produce a lot of slag so I had to clean a lot. I poured standard table salt in the crucible which I read helps to separate the slag from the aluminum and makes the metal easier to pour. Once I melted all the cans I poured the aluminum into the cup cake pan, let them cool about 30min and was done.
If anyone have any ideas on what I should try to cast first I want to hear them.