Polyurethane seals refurbished or new countertops, protecting the surface from water and stain penetration. Countertops refinished with paint do not wear well and will scratch easily. Polyurethane forms a layer of clear protection guarding the fragile painted surface against surface scratches while restoring the shine. For the best sealing and protecting for countertops, use a polyurethane recommended for floors.
Proper preparation is the key to successfully completing the polyurethaning of countertops. Allow proper drying times for each product applied, from the primer to the finish coats of polyurethane. Let a minimum of three to four days pass for drying and hardening before subjecting your counter to light use. Arrange to have a secondary area on which to prepare food to avoid contaminating the counter with cooking oils and water.
Clean the counter by scrubbing it with very warm water and a degreasing product. Tri-sodium phosphate (or TSP) diluted in water thoroughly removes grease and grime. Rinse it off thoroughly.
Priming and Painting
Countertops require lightly sanding to roughen and remove shine from the surfaces. Clean off the sanding dust with paint thinner or mineral spirits before applying one to two coats of primer. Use high quality brushes and rollers when applying primer and paint. The results will be a smooth and professional appearance.
Two coats of finish paint, applied in smooth thin coats, dry faster than one thick coat of paint. Purchase high-quality paint, either oil- or acrylic-based. These paints dry to a harder surface than a latex base paint. Oil and acrylic base paints have strong fumes; ventilate the area adequately.
Apply stencils and faux finishes before sealing the countertop with polyurethane.
Apply clear polyurethane to the countertop after the paint has had adequate time to dry and harden. Polyurethane formulated for use on floors is tougher and resists scratches better than polyurethane formulated for use on woodwork and other similar applications. Consider how much wear a floor in a gymnasium receives and how well these floors shine after abuse from balls and shoes. This is the type of finish countertops require to look their best over time.
Lightly sand the polyurethane between coats for better adhesion of subsequent coats. Two to three coats are recommended.
Lightly sanding the countertop and applying a fresh coat of polyurethane every six months will protect the countertop and keep it looking new.
Always protect the refinished countertop from hot pans and use a cutting board for food preparation. Refinished countertops are not as tough as new laminate, but the cost of refinishing is a lot less than purchasing new countertops.