Polyurethane for wood provides a high-gloss, durable finish. Polyurethane is available in both oil-based and water-based formulas. Oil-based polyurethanes are resistant to water, alcohol and acids. However, the oil-based product turns yellow as it ages. Water-based polyurethane goes on clear and stays clear, but it is not resistant to alcohol and acids. Water-based finishes are also softer than oil-based finishes. While either polyurethane finish gives years of good service with proper care, it sometimes becomes necessary or desirable to remove this wood finish. This task is accomplished through the use of chemical paint and varnish removers and light sanding.
Assemble equipment. Read instructions on your chemical paint and varnish stripper. Put on your protective gear.
Apply stripper using a brush. Stripping product should be thick enough to set for approximately 10 minutes without drying out. Work in an area small enough to be within easy reach, when stripping floors or other large items.
Scrape the area with a plastic scraper or plastic putty knife. Using a plastic decreases the chances of damaging the underlying wood. Remove the softened polyurethane and stripper with soft cloths or rags. Clean the area by wiping with a clean cloth dipped in clear water or according to the instructions on your chemical stripper. Wipe the cleaned area with a dry cloth to avoid prolonged wetness.
Brush stripper onto an area adjacent to the area previously stripped. Allow the stripper to set for 10 minutes, scrape and wipe as before.
Sand the wood using an oscillating tool equipped with a hook and loop pad accessory fitted with 120 and/or 220-grit sandpaper to remove grain raised by the application of liquid. Remove sanding dust completely before applying stain or new finish.
Tips & Warnings
- For best results, ensure the stripped wood is completely dry before sanding.
- Always wear safety glasses when using power tools and chemicals.
- Wear a dust mask when sanding wood.
- Work in a well-ventilated area.
Things You'll Need:
- Chemical paint and varnish stripper
- Paint brush
- 3-inch scraper
- Oscillating tool equipped with a hook and loop pad accessory
- 120 and/or 220-grit sandpaper
- Rags or cloths
- Safety goggles
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