First, be sure to immediately clean up any spills. If you allow excessive moisture or harmful chemicals to remain on a finished wood surface, damage could result. Clean up spills with a damp cloth, then dry the surface thoroughly.
Periodically, apply a coat of spray wax, paste wax or lemon oil to the finished surface. This will enhance and preserve the board’s finish. It will also provide a moisture barrier that will help protect the wood in the event the finish becomes scratched or worn.
Use steel wool or fine grit (#220) sandpaper and a sanding block to remove minor scratches. Always sand along/with the grain and feather the edges of the repair into the surrounding area.
Remove all dust and residue before applying a clear satin or lacquer-type finish, such as MINWAX Fast-Drying Polyurethane. Only touch up the area you sanded. Be sure to follow the manufacturer’s directions for refinishing.
In cases where sizeable portions of wood have been damaged or removed, you should consult a furniture repair professional.