How to Restore Window Sills Before Painting

Scrape away any loose paint chips with your metal scraper. Dispose of all old paint safely in trash cans or trash bags to avoid pets or children from coming in contact with them.

Remove remaining paint with a heat gun. Direct the heat gun at the paint areas until it blisters, and then scrape away the remaining paint. Continue until most of the paint is removed from the surface; a few chips here and there will not harm your painting project.

Probe the surface of the wood with a small screwdriver, looking for soft spots in the wood. If you hit an area that is so soft to the touch that you can penetrate it with your fingernail, you will need to remove it in order to preserve the strength of your sill.

Remove soft areas of the wood by prying them out with the screwdriver. You can also use a chisel or a wire brush to remove these areas.

Fill in any holes in the wood window sill with epoxy filler. This material is available at hardware and home improvement stores. Apply to the holes and smooth over with a putty knife. Allow the epoxy to dry completely before continuing; consult your product for detailed drying time.

Paint epoxy sealant over the surface of the window sill. Also available at hardware and home improvement stores, epoxy sealant will penetrate the wood to prevent rotting or molding after the surface is painted. Allow the sealant to dry completely before painting; consult your product for detailed drying time.