How to Paint Composite Materials

How to Paint Composite Materials Composite materials are mixtures of different fibers bound together by a hardening resin. Depending on the application, composite materials may or may not require painting. Painting is a good way to restore or change the color of the composite after the original finish has faded. The best methods of painting depend on the type of materials in the composite. Following are step-by-step instructions for painting some of the most common composites. You may also want to check with the manufacturers recommendations. Painting Fiber Cement Composites Use a pressure washer to clean. Wait two-four hours for the cement composite to dry.Apply a primer.Wait two hours or so for the primer to dry.Apply the paint same way you applied the primer. Wait about two hours for the paint to dry. Painting Wood Composites For exterior wood composites, use a pressure washer with a low-pressure tip to clean. Wait two hours for the composite to dry.For interior wood composites, dust with a broom.Using a roller, coat with an acrylic latex primer. Use a paintbrush for any areas you cant reach with a roller.Wait two hours or so for the primer to dry.Use satin or semi-gloss latex paint on interior wood composites. Use acrylic enamel on wood composites inside the house. Apply acrylic latex paint the same way you applied the primer. Wait four hours until dry. Painting Composite Decking Mix one part bleach with three parts water.Using rags, a roller, or a brush, apply the bleach solution liberally to all surfaces.After half an hour, scrub the surfaces.Rinse off the solution and residue.Using very fine sandpaper (220 grit) lightly sand all the surfaces.Wash off dust and dirt with a household detergent or commercial cleaner made for cleaning composite decks.Rinse thoroughly.If you are going to paint the deck, prime with an exterior latex stain-blocking primer made for plastic materials. Do not prime if you plan to stain the deck instead of painting it.For painting, use a high-quality latex floor and deck paint in a satin or semi-gloss finish. For staining, use a high-quality acrylic latex solid color deck stain recommended for composite decking. Painting Fiberglass Composites Fill holes or imperfections with fiberglass putty. Smooth out the putty with a putty knife. Let it cure completely.Sand with heavy sandpaper (100 grit) to remove excess putty or any paint. After the composite is fairly smooth, switch to 800 grit sandpaper and sand until the composite is very smooth. You can use an orbital sander or sand by hand.Use a dry rag and acetone to remove dust, grease, and debris.Apply a primer. Most primers work on fiberglass, but its a good idea to double check with the paint store on the best one to use. Wait two hours or so until the primer is dry.Spray or use a brush to apply the final coat of paint. Wait until the paint is dry.Apply another coat of paint or apply the clear coat. Always use a clear coat after the last coat of paint; it will seal the paint and help protect the paint from the elements. Final Words On Painting Composites As with any paint job, thorough preparation is the key to a good looking and long lasting paint job on composite materials. Follow recommended safety precautions on the products you use. For example, wear gloves when working with fiberglass. Wear liquid-resistant gloves using bleach. Wear eye protection when sanding, using bleach, and when working with fiberglass.