I finally decided to build a electric foundry for aluminium casting, rather then charcoal or propane. As you can see from my past startups from my propane foundry, it can be dangerous, also polluting the environment. I always thought the neighbors would call the fire department or something. Its about time I switched.
I bought some heating element and tested it out, it should be enough to melt aluminum. The coil is about 2 meters long and has a resistance of about 15 ohms. This draws about 7.5 amps with a total power of 850 Watts. This might not be enough but I left in excess to experiment with the length later.
Next I found a box that was big enough to make as a base, then tapped all of the openings.
I used Plaster of Paris, Play Sand, and Concrete (to increase the longevity of the furnace). Plaster of Paris should allow the water to seep out so hopefully no explosions. Just to be safe I will heat it up slowly for the first time.
Time to mix everything, I used 1/2 Plaster, 1/2 water, and threw in a cup of concrete per half bucket.
Poured it into the box to 2.5 inches high and let it dry.
Then I put the inner box inside and filled it up the rest of the way. Now its time to let dry and put the heating element in and wire it up.
Im currently in the process of making it, I will post the results soon.