A quick overview of how to cast glass
Glass casting begins with an original clay sculpture with as much detail as possible. A damn is made around the sculpture so that liquid latex can be poured into it, over the clay, to create a negative mold.
Plaster is poured into the resulting latex mold, creating a positive mold that can withstand the heat of the kiln. The plaster cast is carved to smooth out any bubbles or other inperfections and for any embellishments such as added texture.
It’s then filled with sand, which is weighed to determine the exact amount of glass to exactly fill the mold.
The plaster mold is placed in the kiln, and filled with chunks of glass, broken billets. The “Reclining Buddha” required just under 20 pounds of glass. The kiln is heated to around 1500 degrees and annealed (cooled to room temperature) over a period of three days or more.
Once the piece has reached room temperature the plaster is carefully broken off and discarded. The glass is then cleaned with dental tools, toothbrushes, and lots of elbow grease. The final step is polishing. The latex mold can be reused.
For info on fused glass, see my blog post.