Step 1: Strip Away Old Finish
Remove the existing finish on a banister by stripping it off, either by sanding or with a chemical stripper. The more thorough you are during the stripping process, the better your new application of stain will work and look. Start sanding with a medium-grit sandpaper to remove light nicks and dents, and the existing finish. If the banister is round, wrap a piece of sandpaper around the banister so that it covers as much of the banister’s surface as possible. With the sandpaper wrapped around it, move the sandpaper back and forth as you move along the entire length. Banisters with flat surfaces can be sanded with a sanding block. Sand the finish until the wood is bare. Sand the entire surface again with a medium/fine-grit sandpaper and then lightly once more with a fine-grit sandpaper. Ask an expert at your local True Value hardware store which exact sandpaper grit is best for your banister’s wood. If you don’t know the type of wood, it’s best to err on the side of caution and start off with as fine-grit sandpaper as you can use so you don’t damage it. Test it in an inconspicuous area on the banister.