Guide to Refinishing a Table With Polyurethane

Safety

• Finish removers, wood dust and polyurethane finish can all pose health hazards when used improperly. Always use chemicals with fumes in well-ventilated areas. Wear protective clothing, such as rubber gloves, eye protection goggles, a dust mask and long sleeves. Do not store finish removers and finishes in areas where children and pets can access them, and keep them away from fire. Be careful with rags and brushes that have finish remover or finish on them, because they are a fire hazard.

Removing Old Finish

• Sandpaper can remove old finish, but a chemical finish stripper removes old finish with less risk of damage. Sandpaper removes engravings, patina and other desirable details in old wood, so a liquid or gel finish remover is especially important for tables with detailing. Commercial gel or paste chemical strippers soften old layers of finish so it can be scraped off. Liquid finish removers allow the user to scrub away the old finish with a stiff brush.

Wood Preparation

• After removing the old finish, prepare the wood for refinishing by sanding it sparingly to smooth its surface. Use an 80- to 120-grit sandpaper to sand rough areas and remove major imperfections, if necessary. The sandpaper can also help remove leftover traces of the old finish. Use a 150- to 180-grit sandpaper to smooth the wood before applying the new finish. Do not sand the wood more than it absolutely needs to become smooth, because sanding can remove the attractive old patina from the table. The sanding dust that remains will make the new finish less smooth and attractive, so vacuum the workpiece thoroughly to remove all traces of dust before finishing.

Applying the Polyurethane

• Pour some polyurethane into a separate container to keep dust out of the can. It is best to apply the finish in temperatures of at least 65 F, with the ideal application temperature around 70 F. Brush a thin coat of polyurethane finish onto the wood in the direction of the grain, and then brush across the grain. To finish the coat, brush gently with the grain. Let the finish dry completely. Rub the finish very lightly with 220- to 280-grit sandpaper and dust again before applying a second coat of finish. Keep dust away from the wet finish as much as possible by avoiding drafts from open windows.