painting acrylic

PAINTING CHEMCAST® GP CAST ACRYLIC SHEET

Chemcast® GP acrylic sheet can be painted easily to create an almost unlimited variety of decorative and functional products. Chemcast® GP contains no plasticizers or additives to interfere with paint adhesion or affect the durability of paint film, and is no more difficult to paint than common nonplastics such as wood or metal. As with any material, however, proper techniques and paint suited to the application are necessary to successfully paint Chemcast® GP.

It is important that the paint selected for use on Chemcast® GP be designed expressly for use on acrylic plastics. Ordinary house paints and waterbased paints have poor adhesion to Chemcast® GP. Some paints contain organic solvents which may craze Chemcast® GP. Since it is not feasible to test every paint formulation on the market, however, for assurance that a specific formulation is suitable for use on Chemcast® GP in the intended application, consult the paint manufacturer. In the course of developing paint formulations for acrylics, the manufacturers have accumulated much valuable experience, and should be able to make specific recommendations for their products. (Sources of Supply - Paints).

The outstanding durability of Chemcast® GP on prolonged outdoor exposure requires paints that will give equally good service outdoors. This is especially important for the sign industry, which makes extensive use of painted copy to get great flexibility in design and decoration of outdoor acrylic signs.

Because Chemcast® GP acrylic sheet is colorless and transparent, the paint is best applied on the second or inside surface to allow the Chemcast® GP to protect the paint from the elements. The effects of weathering on first surface paint films are more severe than they are on second surface films. First surface films eventually show surface dulling, chalking, and erosion to the degree that repainting is often needed to restore appearance. When the paint is applied to the second surface, the Chemcast® GP protects the paint from the deterioration caused by weathering, but exposes the paint/Chemcast® GP interface to the full sunlight, which may cause loss of adhesion and flaking. This is a severe test of the adhesion of paint film.

Extensive testing, confirmed by long service experience, proves that paints designed for use with acrylic plastic have the adhesion and durability necessary for second surface painting of Chemcast® GP. These paints can, of course, also be used for first surface painting.