Painting Over Resin-based Venetian Plaster

Preparation

• The protective wax placed on top of finished Venetian plaster must be removed prior to painting. Keep in mind that the plaster beneath the wax must be protected. This plaster is simply a mixture of marble dust, paint and resin. If water penetrates the mixture, then the plaster may soften and break up. Remove the wax with an organic wax stripper. Spray on the stripper with a spray bottle. Gently scrub the wax with a soft-bristled brush and wipe way the remains. Work in small areas no larger than 24-by-24 inches. You can complete the stripping of a 12-by-12-foot room in less than eight hours.

Drying

• When the wax has been removed, the plaster surface will remain wet from the stripping process, and the plaster may have softened as a result. Dry the plaster slowly with box fans. Generally, two box fans per 12-foot wall will dry the wall in one to two hours. Open all windows in the room to help the air to circulate. However, if conditions outside are moist and damp, leave the windows closed. Direct the fans onto the plaster, placing them no closer than 5 feet. The plaster will lighten in color when it has dried. If space permits, you can use the room during the drying process. However, take care not to touch the walls.

Protectant

• Apply three coats of matte clear-coat finish, allowing 30 minutes drying time between coats. Generally, one gallon of clear coat will cover 400 square feet, so a 12-by-12 room will need 3 gallons of clear coat to cover four walls three times. The clear coat will protect the delicate plaster while allowing the surface to be painted. Additionally, matte finish holds paint well without requiring any surface preparation, so no sanding or surface preparation is needed. Spray on the matte clear coat with an electric sprayer, holding the nozzle 8 to 12 inches away from the plaster. Allow four to six hours drying time before painting the plaster.

Painting

• Paint over the sealed plaster with oil-based paint. It will dry slower than water-based paint. However, it will also serve to further protect the plaster with an oil finish. Oil-based paints dry harder and last longer. Apply three coats, allowing one hour drying time between coats.