For the furnace, two five gallon metal buckets (with lids) were used, a piece of 3-inch stove pipe, hair dryer, and of course, some duct tape.
For a crucible (the little bucket that holds the melted metal), a 16 oz propane bottle was used; the top was cut off and some bolts were added for grabbing the crucible with the tongs.
I made some basic tools with some scrap steel from an old bed box spring. You'll need tongs for the crucible, some kind of shepard's hook to tip the crucible when pouring, and a plain rod with a little bend at the tip for poking things and skimming out the dross (impurities in the aluminum).
Use of this equipment shown is dangerous because of very high temperature molten metal, fumes and smoke, etc. Use caution and be safe by wearing leather gloves, face protection, and other protective clothing. Do this outdoors and use it when it's a little windy so the smoke and fumes quickly dissipate, also use this during dry conditions because dripping molten metal on wet surfaces can cause little hot metal explosions (like water and hot oil in the kitchen). I'm not liable for any injuries you may occur using the equipment and techniques shown here.
Read, read, read lots of metal casting stuff before starting.
Casting Aluminum at submarineboat.com
BackyardMetalcasting.com ...Melting and casting metal yourself
Here's a silent movie of the foundry at work.
Step 1: The furnace
The hair dryer needs to have the "cold" button taped for use as just a blower; tape the hair dryer into the stove pipe, then insert the pipe into the bucket . Air flow is the most important part of this, I first used a little 1.5 inch pipe, but it just wasn't enough air volume to get the charcoal really nice and hot.
The bottom of one metal bucket is cut off about 2 inches from the bottom; a lot of holes are punched in center 6 inches of that piece and it's inserted into the main bucket as a burning base.
Keep the lids, one lid should have a 3 inch vent hole in it for burning and the other lid should be left unchanged for snuffing out the fire.