How to Apply Oil-Based Polyurethane

A woman works on a table.
What You'll Need
Oil-based polyurethane
Sandpaper (100, 150 and 220 grits)
Wet/dry sandpaper (400 grit)
Mineral spirits
Clean, lint-free cloths
Tack cloth
Sanding block
Wet/dry vacuum
Breathing mask
Razor blade
Automotive rubbing compound
Automotive polishing compound

Oil-based polyurethane protects wood furniture as well as enhances the natural wood appearance. The finish is clear and shows off the grain of the wood. To apply oil-based polyurethane to your furniture, follow the directions in this step-by-step guide.

Step 1 - Sand the Wood Surface

Sand the surface of the furniture until it is smooth.

Step 2 - Clean and Vacuum the Dust

Use a cloth and shop vac to remove dust from the furniture.

Step 3 - Seal the Surface

Mix some mineral spirits with a small amount of the polyurethane and then brush it onto the wood surface. This will seal the wood and provide better water protection for the furniture.

Step 4 - Apply the First Coat

After the sealer dries, brush on the first coat of oil-based polyurethane. When applying the finish, use long and even brush strokes.

Step 5 - Sand Again

After the first coat dries, sand the entire surface of the wood again. Start with 100-grit sandpaper and work your way up to 220- (or higher) grit paper.

Step 5 - Apply More Coats

Apply two to three more coats of polyurethane. Sand in between coats with higher grits of sandpaper, and wet-sand with 400- (or higher) grit sandpaper before you apply the final coat. Use the razor blade to gently scrape away drops of polyurethane. Carefully apply the last coat of oil-based polyurethane. Lightly wet-sand again.

Step 6 - Clean Up and Polish

Use rubbing compound and polishing compound to polish and shine the furniture.