Replace any sections or panels that have black knots or knots with cracks in them. Sand the entire wood surface to be varnished with fine sandpaper or a sanding block. Use an electric palm sander if you have one available. Sand in the same direction as the grain on the wood.
Wipe the sanded surface with a soft, dry cloth and then wipe it again with a tack cloth to remove all sanding dust.
Apply an even coat of oil-based or water-based polyurethane or spar varnish to the sanded wood with a natural-bristle brush. Allow the varnish to dry for at least 12 hours. Clean your brush with mineral spirits for oil-based finishes or a soap and water solution for water-based varnish.
Lightly hand-sand the varnished surface. Wipe it with a tack cloth. Apply a second coat of varnish with a natural-bristle brush. Clean your brush as soon as you are finished. Allow the surface to dry for 12 to 24 hours before sanding again and applying a third coat if desired or before using your varnished furniture.
Things You Will Need
- Fine sandpaper or abrasive pads
- Hand-sanding block or electric palm sander
- Tack cloth
- Polyurethane or spar varnish
- Natural-bristle paintbrush
- Mineral spirits
- Use an interior-exterior varnish even for indoor furniture. It protects far better and requires less maintenance than an interior-only varnish or furniture varnish.