Here I'll show you how to make a furnace for melting aluminum. The materials can be bought from Wal-Mart and your local hardware store. Cost to build furnace alone: $23 Cost of furnace and materials + tools to operate it: $50
*** 5/31/09 *** I will be making a new, revised charcoal foundry instructable as soon as I get some spare money. This setup is adequate, but there's always room for improvement.
Step 1: Materials and Tools
Required to build furnace...
-One normal sized coffee can (6")
-One hair dryer with a cool mode and preferably two speeds
-One 1.5" x 10" galvanized/black iron pipe nipple
-One soup can
Required to operate furnace...
-Long tongs or pliers to grip crucible
-Steel spoon w/ holes in it
-Heavy leather work gloves
Step 2: Making the furnace shell
Using the tin snips, cut out a square/circle (square is easier!) in your coffee can. Make sure it's big enough to accept your size pipe nipple. (In my case 1.5")
Step 3: Making the forced air blower assembly
To make your blower, take the duct tape and connect the hair dryer to one end of the iron pipe nipple. Turn it on and check for leaks.
Next, use a little piece of tape to make sure the cool button will be held down constantly.
Step 4: The Crucible
Our crucible here is simply a tin/steel soup can. They're cheap/free, they melt at a higher temperature than aluminum, but they're one time use. Don't attempt to use it twice or it will melt through spilling your precious aluminum on your furnace.