Monday, July 09, 2007

Casting with glass and leaded crystal

The model for "ON A Roll" was fabricated from 15 pound sign foam. The sign foam was turned on a lathe, sanded and sealed with shalack. The first mold was a plaster, silica mix. This presented a problem, the rigid sign foam material was difficult to remove from the finished mold. After about 30 minutes of pulling, tugging and wiggling, I succeded in releasing the model from the mold without damaging either.

However, it was obvious I needed to re-think the model material. Something flexible was needed. So, I put a 1/4" clay blanket over the original model and built a plaster case over that, this left me with a 1/4" space to pour rubber over the original model. When the plaster case was dry, I removed the clay and set the plaster case over the original model. Through a hole I created in the plaster case, I poured the silicone rubber. This gave me a thin rubber mold in which I would pour a liquid rubber. The end result was a strong, yet flexible model.

Below is the finished rubber model and a mold made from R&R Glass Cast 910.


alp said...

I reviewed your write up on casting with glass and leaded crystal, but didn't see any connection to glass casting. Do you thin cast a glass part in our silicone mold?

Terri Stanley's Cast and Kilnformed Glass said...

The silicone is a mold for a urethane model. Then the plaster/silica mold material is poured over the urethane model. Once dry, the urethane model is removed and glass or crystal is placed in the mold and moved to the kiln for firing.