Polyurethane plywood is vulnerable to moisture damage, so waterproofing it is essential. Several different solutions are available, but the best one depends on how it will be used and the environment in which it will be located. These include varnish, acrylic and polyurethane coatings. Each has advantages and disadvantages, and each requires proper preparation to ensure the final product is both durable and attractive.

Varnish is more flexible than paint, which helps reduce cracking if the plywood moves. It also lasts longer in areas that receive a lot of sunlight, as the natural solids in it block the UV rays that cause fading and aging. However, it takes longer to dry than other finishes, so you need to plan ahead and be patient when working with it.

Enhancing Plywood Durability with Polyurethane Coating

Acrylic and polyurethane coatings are the most popular for interior use, as they offer a clear finish that allows the beauty of the wood grain to show through. They also have a quicker drying time than varnish and are more resistant to chemicals and water than stain and paint. Polyurethanes come in oil- and water-based versions, with both providing a strong protective finish and a range of sheen options. Water-based polyurethanes are less toxic, releasing fewer volatile organic compounds than their oil-based counterparts.

The key to a smooth, blemish-free finish is good sanding before adding stain or paint and hand sanding after the first coat of polyurethane has dried. You should also make sure to prepare the surface properly for applying the polyurethane, which includes cleaning up any sanding dust and allowing enough time for it to fully dry between applications.