Peeling and scratching off layers of old wallpaper may render the walls beneath coated in adhesive. Worse, it may leave them scarred from your efforts to eliminate every last shred of paper. Before you can paint over these wounded surfaces, then you must return them to perfect smoothness. As with most finishing jobs, preparation is crucial for painting, and also the level of your paint project depends upon the time and effort that you put into patching and sealing.
Dilute 5 oz of wallpaper stripper in 1 gallon of water. Fill a pump sprayer using the mix. Spray the walls together with the mix. Scrape any residue and wallpaper scraps off the walls with a broad scraper knife.
Empty the pump sprayer and refill it with fresh water. Spray the walls to rinse them. Scrub the surface with a wet sponge to remove any remaining residue. Allow the walls to dry for one to two days.
Sand the walls using a sanding block wrapped in 120-grit sandpaper. Apply a coat of oil-based paint to the walls using a roller. The oil-based paint acts as a sealant to lock in any grease stains, stains or water-based adhesive so they do not float after to interfere with the paint job. Enable the paint to dry.
Analyze the walls for flaking or loose bits of paint. If you discover any, sand them off. Repaint the areas together with the oil-based paint and a paintbrush.
Fill any tiny holes, cracks or dents in the surface with joint compound. Apply compound into the holes using a putty knife, then use the knife to scrape off the excess. When the joint compound is dry, then you’re ready to paint the walls.