Wood walls become popular in the 1970s. The panelling is designed to look like real wood with a faux wood grain texture and grooves every six to eight inches. The panelling can be painted with good results. But paint won't cover up the grooves. The only way to fill the grooves is by applying plaster to the walls and then painting over them. Real wood panelling can be plastered and painted using the same techniques.
Mix trisodium phosphate with water according to package directions. Dip a rag into the mixture and wipe the walls clean to remove grease and residue.
Attach medium grit sandpaper to an electric sander. Sand the surface lightly to create texture and allow the primer to adhere to the surface. Remove sanding dust with a damp cloth.
Cover all of the grooves in the wood with mesh tape. Mesh tape is the same tape that is used to hide the seams in drywall. Run a length of tape along each seam, pressing it firmly into place on the wall.
Roll on primer with a 1/4 inch nap roller. Choose a primer that will adhere well to slick surfaces. Apply enough pressure so that the primer sinks in between the grooves in the panels. Allow the primer to dry.
Stir pre-mixed drywall mud with a stir stick. Pour the paste into a paint pan. Roll a looped roller through the mixture and apply to the walls. Go over the same spot on the walls until the grooves are filled and the finish is smooth. Apply the mud to the entire wall. Let the mud dry overnight.
Apply primer to the wood panels with a 1/4 inch nap roller. Use the same primer used before or choose any latex primer. The main purpose of this primer coat is to prevent the drywall mud from altering the colour of the paint. Let the primer coat dry for four hours.
Paint the panels with interior latex paint. Roll the paint onto the walls with a 1/4 inch nap roller. Let the first coat dry completely. Apply a second thin coat of paint. Let the final coat dry overnight.