Friday, April 16, 2010
Here is the original in foam. Glued together with hot glue
I add a pour spout to get a mass of metal to fill the mold.
here it is coated in plaster. Note the straw. Any "high" points need to be vented in order to fill. In this case the important point is the tip of the nose. I then drill holes through the plaster. This allows the steam created when the hot metal hits the plaster to escape.
I heat the mold in a fire to burn out the foam in advance. (not the standard method for lost foam) Then I bury the mold in regular play sand.
The metal is heated with this simple diy home casting furnace using regular charcoal and a normal can that food comes in. Zinc can be scraps or from Rotometals.com.
I then pour in the molten zinc into the mold. A video of another pour back when I used a regular fire.
Here it is after pouring the metal. The little spikes are where the mold was drilled
After this the bull is cleaned with a wire brush and given a coat of clearcoat.