Both paint- and stain-grade plywood are used extensively in home construction. Items like cabinets and panelling are often made from it. Completing the finish work on your interior plywood before installation is the simplest method. Sanding dust and paint fumes can be destructive to carpets, drapes and other interior surfaces without proper masking. Dust masks, safety goggles and proper ventilation are the keys to proper finish work.
Lay plywood flat on sawhorses or other flat, sturdy surface. For pieces that are already installed, apply masking tape around the edges of the plywood and lay out plastic dust sheets to protect the flooring and other surrounding surfaces.
Sand the plywood thoroughly. Start with 80-grit sandpaper on a random orbit sander to remove old finish. If your plywood is unfinished, proceed to the second sanding. Sand finished plywood until the finish is completely removed.
Use 120-grit sandpaper for the second pass, working in long, straight strokes, with the grain of the wood. Keep the sander moving and try to sand the surface as evenly as possible. Wipe the surface with a tack cloth to remove dust before staining.
Apply a coat of stain to the entire surface of the plywood in your choice of colours. Use a medium-sized soft-bristle brush, working in long, straight strokes in line with the grain. Apply the stain as evenly as possible to prevent runs and drips. Wipe excess stain from the surface with a clean, dry, lint-free rag.
Brush on two to three coats of semigloss clear finish with a disposable brush. Work in long, straight strokes in the direction of the grain and keep the finish as even as possible to prevent runs and drips. Allow the recommended drying time between coats.
Mask and sand the plywood as previously outlined. If your old paint is cracked or peeling, use a thin scraper to scrape loose paint from the surface before sanding. Sand until all loose paint is removed. Rub the surface with a tack cloth to remove dust before priming.
Roll on a coat of oil-bonding primer to the surface of the plywood. Roll the primer as evenly as possible to prevent runs and drips. Allow two hours drying time before paint application.
Apply two coats of semigloss latex interior trim paint. Use a medium-sized soft-bristle brush, working in long, straight strokes with the grain of the plywood. Spread the paint as evenly as possible to prevent runs and drips. Allow the recommended drying time between coats. Apply a third coat if needed for dark colours. Allow the paint to cure for 24 hours before normal use.