If you try to apply a light color of stain over the top of an existing dark finish, you won't notice much difference. To completely alter the color of the finish, strip down the existing stain using a petroleum-based solvent. Once you've lightened the wood, you may add a lighter color of stain. While runny, liquid stains are well suited for softwoods, they tend to dry unevenly on most types of hardwood. For a light-colored, uniform finish, choose a specific type of stain that will look beautiful on both softwoods and hardwoods.
Things You'll Need
Paint stripping solvent
Light color of gel stain
Wear a protective respirator and gloves. Remove the polyurethane finish by sanding the wood using a power sander equipped with 50-grit sandpaper. Be sure to move the sander toward the wood grain or unnecessary damage could result. Smooth the wood by sanding with 100-grit sandpaper.
Wipe away sawdust from the wood using tack cloths.
Lighten the dark wood stain by scrubbing it with a stripping solvent, using a nylon pad. Stop once the wood appears light. Wait an hour for the solvent to evaporate.
Apply a light color of gel stain to the wood using a natural brush. Immediately wipe the gel off the wood using rags.
Wash the light gel stain from the brush using mineral spirits. Let the light color of gel stain dry for four hours.
Brush on a coat of polyurethane sealer using the natural brush. Move the brush toward the wood grain. Let the sealer dry for two hours.
Always wear a respirator when working with stripping solvent or the fumes may overwhelm you. Likewise, wear rubber gloves, or you could suffer a rash or burns.