Creating Plaster Negative

Once the permeability of the plaster positive has been sealed with shellac, it is placed on a sheet of plastic on the floor. Any undercuts are filled with wet clay. A wooden form is built around the plaster positive. Several coats of mold release is applied to the plaster positive and then the form is filled with fluid plaster. Once the plaster has set up, approximately 2 hours elapses while the plaster hardens a little more before de-molding.

Plaster Positive
Using regular dishwashing soap as a mold release.
This did not work so well an I have since been using a commercial mold release.
December, 2000.
Clay for Undercuts
Clay is pressed around the edge of the form and into any undercuts.
December, 2000
Building Mold Box
Building the mold box from 2 x 10.
December, 2000
Mold Half Full
Mold half full with plaster.
December, 2000
Mold Full
Mold full with plaster. On this paticular project the form leaked spilling lots of
plaster all over my basement. Eeeee!
December, 2000
Completed Plaster Negative
Plaster Negative.
December, 2000
Show me another example!