How to Restore Polyurethane Finish

Polyurethane makes a durable floor finish.

Polyurethane is polymer plastic that can be dissolved in oil-based solvents or water to produce a durable and attractive finish for floors. The finish will last for years, but eventually it will need to be touched up or completely redone. If you want to avoid completely sanding the floor, you will have to check first to ensure that the floor does not have a layer of wax that will prevent a touch-up coat from adhering.

Things You'll Need

• Oil- or water-based polyurethane floor finish
• Paintbrush
• Hardwood floor cleaner
• Rag
• Floor buffer
• 120-grit buffing screen
• Orbital sander
• 120-grit sandpaper
• Lambswool applicator
• Respirator

Instructions

1. Test the adhesion of the polyurethane by painting a small, inconspicuous area. Wait 24 hours and check to see if it peels or lifts off. If it does, you will need to sand the floor and refinish.

2. Clean the floor thoroughly with hardwood floor cleaner and a rag.

3. Buff the floor with a 120-grit screen. Use an orbital sander with 120-grit sandpaper to reach the edges and corners. Vacuum the dust off and wipe the floor thoroughly with a damp rag.

4. Apply a coat of polyurethane with a lambswool applicator. Use a paintbrush to apply finish to the edges and corners of the room. Let it dry for at least 24 hours.

5. Examine the floor for signs of orange-peel, bubbling or peeling. If there is extensive evidence of any of these conditions, it's probable the finish isn't adhering properly and you will have to sand and refinish the floor. If there are only occasional bumps, rebuff the floor with 120-grit paper and apply a second coat.

Tips & Warnings

• Be sure to give yourself an exit when you are applying finish to the floor.

• Oil-based polyurethane contains isocyanates, which are harmful to the respiratory and central nervous systems. Wear a respirator while applying finish and seal off the room from the rest of the house while the finish is drying.

References

• Naturalhandyman.com: Maintaining and Recoating Polyurethaned floors
• Hardwoodinstaller.com: Water-Based Floor Finishes
• Hardwoodinstaller.com: Oil-Based Floor Finishes