You can re-stain your window sills to create a refreshed look at the base of your windows. Window sills can become worn from potted plants or pets resting there because they like to take in some natural light. It is important to keep your window sills protected by maintaining the finish. Re-staining window sills is similar to re-staining wood furniture. Carefully remove the old finish to make for an attractive refinishing project.
Apply wood stripper to the surface of the window sill with a paintbrush. Allow the stripper to sit on the window sill for the time directed on the container or until the finish is bubbled up and loosened from the wood.
Scrape off the loosened finish with a round edged scraper in the same direction as the grain of the wood. Continue scraping until all of the loosened finish has been removed.
Dip a steel wool pad into the wood stripper and lightly rub any areas that still have finish on them to help remove the finish.
Sand the stripped surface with a progression of 120 to 220-grit sandpaper until the surface is free of all of the old finish and is completely smooth. Wipe the surface of the window sill off with a tack cloth.
Rub gel stain into the window sill with clean rags in an even motion to achieve the desired finish. Allow the stain to dry for 72 hours.
Apply a clear polyurethane finish over the stained windowsill with a paintbrush. Brush on up to three coats. Allow the finish to dry for at least four hours between coats. Sand between each coat using 220-grit sandpaper. Wipe the dust off with a tack cloth.
Refinish your window trim to match the window sills.
Apply stripper, stain and polyurethane in a well-ventilated area. Wear eye, hand and face protection when working with wood strippers.