A durable top coat, polyurethane roof coating gives a beautiful sheen to plywood and adds a protective layer that resists moisture and stains. It is often used on wood floors and smooth furniture but can also protect outdoor decks, although for this purpose you may want to consider a UV-resistant polyurethane. The best way to refinish your plywood is to apply thin coats, sand in between and let the finish dry thoroughly according to the manufacturer’s instructions.

When compared to traditional varnishes, urethanes are typically harder and more chemical resistant. For these reasons, they are often chosen for demanding niches like marine use or for high-traffic areas of the house. When deciding on which type of urethane to use for your project, start by thinking about what you want the finish to look and feel like, as well as its durability.

Polyurethane Plywood Sealer: Protecting Your Projects for the Long Haul

Oil based polyurethanes will usually have a warm, amber hue to them and can cause yellowing over time, so they are less suitable for use on light colored furniture. However, they are extremely durable and will offer a more durable film over your wood than water based polyurethanes.

Depending on the brand, some oil based polyurethanes can be applied using a synthetic bristle brush or a foam roller. Other options include spraying the product or wiping it on with a cloth. Spraying will give you a more even finish and can reduce brush strokes, but requires ventilation and the use of an industrial face mask to prevent exposure to volatile organic compounds (VOCs) during application and clean up.