How to Apply Polyurethane to Furniture

Polyurethane is a liquid sealant that can add gloss and shine to your piece of furniture. Whether your furniture is bare, stained or painted, a top coat of polyurethane is ideal for dressing up your chairs, tables or other furniture. Because the chemicals in this material can be a bit overwhelming, it's always best to use polyurethane outdoors or in a well-ventilated work space.

Polyurethane can revitalize an old or unsealed piece of furniture.
  1. Decide whether you want a water- or oil-based polyurethane. Oil-based products are generally rated as stronger and longer lasting than water-based products. They are especially useful for furniture that will be used outdoors or exposed to moisture and humidity. Water-based polyurethanes rarely yellow or discolor the finish of furniture. They often contain a less harsh scent than oil-based products.

  2. Prepare the surface of the furniture you want to seal. A polyurethane coat is only as good as the prep work that precedes it. Sand down the area with fine-grit sandpaper to help the varnish adhere properly. This will also remove imperfections that might be more noticeable after the varnish has dried. Remove any dust or dirt with a warm, damp washcloth.

  3. Apply the polyurethane with the grain of your furniture, using a sponge brush. Dip the brush halfway into the can and scrape it against the side of the can to push off excess liquid. Apply an even layer over the furniture's surface.

  4. Allow your first coat to dry completely. If you see imperfections in the wood, you might sand it down again and start over. Again, good and even sanding is the only way to ensure the best results with your polyurethane finish. Allow each coat to dry before adding another coat.

About the Author

Liza Hollis has been writing for print and online publications since 2003. Her work has appeared on various digital properties, including USAToday.com. Hollis earned a degree in English Literature from the University of Florida.