How to Repair the Finish on Pella Sliding Glass Doors

Fill any holes or cracks in the wood with wood putty. Use a putty knife to work the putty into the hole. Run the blade of the knife across the wood's surface to remove any excess putty. Allow the putty to dry according to package instructions -- usually one hour.

Sand the wood surface using 180-grit sandpaper. Smooth the putty patch with the sandpaper and remove the previous finish. Dust the wood with a tack cloth to remove the sanding dust.

Apply a wood conditioner to the wood with a soft cloth and rub it into the surface. Allow it to sit on the wood for a few minutes and buff off any excess.

Wipe stain onto the wood using a rag. Work with the wood's grain while applying a liberal amount of stain. Allow it to sit on the wood for the time recommended by the manufacturer. The longer it sits on the wood, the darker it will get. Buff off any excess stain and allow it to dry.

Seal the wood by wiping polyurethane finish on with a rag. Apply the finish quickly, using a circular motion. The finish dries rapidly. Apply three coats for extra protection.