How to Varnish Teak

Sand the teak wood with 120-grit sandpaper to remove any imperfections in the wood surface. Remove any paint or existing varnish from the wood.

Sand the teak with 220-grit sandpaper to create a smooth, finishable surface on the wood. The 220-grit sandpaper will remove any imperfections on the surface, leaving the wood free of blemishes.

Wipe off any dust from the surface with a damp towel. Soak up extra moisture from the wood with a lint-free towel. Allow the wood to dry completely before continuing.

Stir the polyurethane with a paint stir stick. Stir slowly to avoid creating bubbles in the polyurethane, as these can transfer into air bubbles on the teak once applied.

Dip the tip of the foam paintbrush into the polyurethane. Wipe excess polyurethane from the tip of the brush and re-dip the tip into the polyurethane. Wipe excess polyurethane from the tip of the brush by using the rim of the can.

Apply polyurethane over the entire surface of the teak wood. Lightly coat the surface with a thin layer of polyurethane. Avoid adding a large amount as this will cause an uneven surface finish, creating an unattractive finish.

Run the foam brush in the same direction as the grain to avoid bubbling of the polyurethane. Allow the polyurethane to dry for six hours and then apply a second coat. Consider applying two or three thin coats of polyurethane over the teak to prevent bubbles and buildup. Allow the teak to dry for 24-hours before placing any items on the surface.