How to Remove Polyurethane From Countertops

Slip on gloves and protective eyewear. The chemicals that fill chemical strippers are highly corrosive, so you shouldn’t allow them to come into contact with your skin or leave your eyes uncovered. If the chemicals splash back into your eyes, you could suffer serious injury.

Sand the surface. Using 220-grit sandpaper; break the surface of the polyurethane. You are not attempting to sand away all of the finish, just mar the surface so the chemical stripper you apply can sink in and eat away at the polyurethane.

Apply the chemical stripper. This compound comes in both paint-on and spray-on versions. Before selecting your stripper, carefully read the package and ensure that it is indicated for use on polyurethane; if it isn’t, it likely won’t be strong enough to remove it. Apply the stripper per package instructions.

Scrape away the polyurethane with a putty knife. After waiting for as long as the package indicates, your polyurethane should soften and bubble. With clean, smooth strokes going in the direction of the grain (if your countertop is wood), remove this bubbled-up polyurethane.

Sand the surface once more to remove any remaining polyurethane. Wait until your newly stripped countertop is dry before tackling this task, as it will be difficult to tell where polyurethane remains while the counter is still wet. Look particularly for spots that are shiny, as this indicates that polyurethane is likely still present. Sand until all traces are removed.