Surface must be clean and free of wallpaper, loose paint, loose plaster and all foreign material.
Undercut edges of existing plaster so patch anchors around opening.
Lightly dampen with water the area to be patched.
Add DAP Plaster of Paris to clean water in a clean container mixing 2 parts powder to 1-partcold water (40°F to 50°F). Stir to a smooth consistency. Do not mix more material than can be used in 6-10 minutes. Discard any material that has begun to harden.
Apply the DAP Plaster of Paris with a clean putty knife or trowel filling around edges. Remove excess material so that plaster is level and flush with the surface being patched.
For large, deep openings apply a base layer and allow it to dry. When the base layer is dry, wet the surface and apply the finish layer to patch. When thoroughly dry, sand smooth. Make sure the plaster is completely dry and hard before painting.
The mold should be clean and free of loose material. For most uses, wetting the inside of the mold prior to pouring is sufficient. However, when a super-smooth surface is desired on your finished piece, a coat of mold release is recommended instead of water. A suggested mold release is a mixture of mineral spirits and petroleum jelly mixed to a watery consistency and applied with a brush to the inside of the mold.
Wet inside of mold for easy removal after drying.
Fill mold one quarter at a time, tapping on tabletop to release air after each fill.
After 1 hour remove the dried Plaster of Paris from the mold. Allow the cast to dry 1 to 3 hours depending on size.