For banisters and other home projects, it may take quite a bit of sanding to remove a high gloss varnish.

Kitchen in luxury home with stone fireplace

Once the wood is sanded and cleaned, fill in any holes or cracks and prime with a stain-killer primer. Be sure to select a primer that works with the stain you’re painting over (oil-based or water based), as well as the paint you’re using on top. Primer is especially important if you’re paint is a lighter color than the old stain.

After the primer is dry, paint the wood using a high quality paintbrush using several thin coats. If you are looking for a super smooth finish, use three or more coats, sanding in between each coat. Once the paint is completely dry, you can protect your piece with a coat of clear varnish or polyurethane. Once you learn how to paint over stain your whole DIY world opens up!  Good luck on your furniture upgrade.  

Unsure if you want to paint over stain?  Learn more here, What is the difference between Staining and Painting?