Going from dated, paneled wood walls to brightly painted ones is a dramatic change. The key to a great looking job is taking the time to prepare the paneled walls properly. Use some tricks to make it go faster and better. Finish the job with a washable matte paint to disguise any flaws in the paneling.
Go over the paneling with finishing nails and a hammer to make sure all the seams are tight and no nails are sticking out.
Combine washing and sanding the paneling into one-step. Mix a solution of water and a heavy-duty degreasing cleaner. Thoroughly scrub the walls down with the flexible sanding sponge. They hold up quite well in water. Rinse and let dry naturally. Drying with a rag will leave little fibers that will show up in the paint.
Prime before you fill and caulk the paneling to expose the holes and gaps in the paneling that might not be visible against the dark wood. Use an oil-based primer because some paneling will bleed through water-based primers.
Once the primer is dry, caulk all the gaps you see along the top of the baseboards, crown molding and seams. Fill the holes with filler compound. Put a tiny dab of compound on your finger and push it into the holes, smoothing as you go. Sand lightly to smooth, if needed.
Paint the paneling. Cut in with a trim brush and finish with a lambswool roller, which will hold more paint than a synthetic roller and get into the groves of the paneling. If some of the crevices are deep, turn the roller sideways and slide it up and down the groove to push the paint in. Count on two coats of paint for complete coverage.