Chalk Casting

Lesson: Chalk Casting

·         Spray your mold with mold release.

·         Mix Plaster of Paris with water (4:3 ratio, or to the consistency of sour cream/greek yogurt)

·         Add any powdered color (powdered tempura is perfect for this, especially if you plan on using the chalk) and mix thoroughly

·         Pour into mold and tap gently against table to settle the plaster and bring any bubbles to the surface.

·         Let cure- 1-2 hour in the mold, then let sit undisturbed for another 4-6 hours before using.

·         After the plaster is set but still finishing curing, it will be cool to the touch. Once it stops being cool and goes to room temperature it is completely finished curing.

Let any remaining plaster cure and dispose of in the trash!!

Working with the castings:

·         You can embed objects into the chalk to be exposed as it wears away.

·         You can also imbed findings into the back of the chalk by placing them in after you cast and before the material cures. Any findings embedded this way should have a pin or rod that extends into the casting for stability and adhesion. Simply placing a pin back or jump ring on the surface is too fragile.

·         You can drill into the chalk- gently!

·         You can also carve the chalk using burs or wax tools.

·         Finish the chalk with gentle sanding- it wears away quickly!