You can melt and cast aluminum in your home safely if you have the right materials and use appropriate precautions. You will need a metal melting furnace to bring the scrap aluminum to temperatures above 1,220 degrees Fahrenheit, the point at which aluminum melts. You also need a box filled with sand to make the mold into which you will pour the aluminum. This type of casting is called sand casting.
Preparing The Mold
Fill a wooden crate with dry sand. The level should be deep enough to contain the shape you want to make with the melted aluminum and still leave a few inches of sand beneath it. This will protect the wooden bottom from the extreme temperature of the melted aluminum.
Place the crate on a table a few feet away from the metal melting furnace. Make sure the space between the furnace and the table is clean and dry. You will have to carry a crucible containing melted aluminum across this space. Pack the sand down firmly.
Make a mold by pressing an item into the sand to make a cavity with the same shape. For your first attempt, briefly embed the bottom of a can or a piece of jewelry in the sand. Remove the object and set it safely out of the way.
Melting and Casting the Aluminum
Don safety glasses, long pants, a long sleeve shirt and a pair of gloves. Metal melting furnaces are used safely all the time, but they reach high temperatures that could cause severe burns if used unwisely. The melted aluminum may splash if it makes contact with a nonporous surface and water. Keep the area around the furnace and the casting mold completely dry.
Clean dirt and debris from the scrap aluminum. Dry it thoroughly. Place the aluminum in the crucible.
Put the crucible in the metal melting furnace. Bring the temperature to a minimum of 1,220 degrees Fahrenheit. Wait for the aluminum to melt completely.
Turn off the furnace. Remove the crucible holding the melted aluminum. Pour a teaspoonful of borax into the molten aluminum. This will dissolve oxides and other dross remaining in the aluminum.
Carry the crucible carefully over to the box filled with sand. Pour the melted aluminum into the cavity you previously made. Do not tamper with the aluminum. It will level out on its own.
Allow the aluminum to cool. Remove the cast aluminum from the sand. Brush off any sand particles that have clung to it.