Wood looks great in any color with correctly applied paint. Painters learn the secret to a fantastic paint job is prep. The current finish and the kind of wood ascertain what preparation is essential before painting wood. Plywood, particleboard and walnut walnut want more prep that quality hardwoods, but all kinds of wood can appear equally smooth under a painted wood finish.
Safety First
Wear a dust respirator and safety goggles or safety glasses with side shields while cleaning and sanding. Use a compound respirator when working together with the solvents on sealers, primers and naphtha. Wear rubber or plastic gloves for all wood finishing tasks, not just for the sake of your palms, but also to safeguard the wood surfaces from the natural oils of your palms. Keep the work area clear of debris, tools and cords.
Filling
Fill nail holes with wood putty. Avoid overfilling since putty expands. Squeeze extra filling off the surface of the hole with a putty knife. Fill large knot holes on flat surfaces with spackling compound and a putty knife. Use the spackling to create smooth edges and sharp corners on manufactured wood products and plywood. Use a gloved finger to disperse spackling over router-beveled edges. Allow to dry for a hard surface.
Sanding
Sand wood down to a smooth surface in stages, with a development of coarse, medium and fine sandpaper. Sand with the grain to prevent visible scratches from the painted wood finish. Sand fillings flush with the surfaces. Use a router with a matching bit to sand the spackling onto a beveled border. Use a vibration breaker or random orbital sander for flat surfaces. Sand hard to reach crevices with an oscillating tool fitted with wood sand paper attachments.
Finishing
Scrub new wood with naphtha to take out resin prior to finishing wood. Seal all surfaces with a shellac sealer to prevent oils and resin from soaking through the end. Allow to dry to touch and sand smooth before applying another coat. Apply a primer on the sealer and let it dry thoroughly before painting wood. Apply a couple of coats of paint allowing each to dry before applying the next.