Water-based polyurethane is clear and will remain clear overtime, while oil- based polyurethane generally has a yellow tint to it that intensifies the color of the wood overtime. Another consideration when determining which base is best suited to your needs, is what you need the finished surface for.
Simply place a few drops of water on the wood surface and wait for a couple of minutes. If the water beads up, the wood likely has a finish, such as varnish or polyurethane.
Learning how to apply polyurethane can give wood furniture and flooring a glossy, smooth finish while improving its durability. Read on for steps on how to apply polyurethane to furniture, plus tips for getting professional results.
The application process can be time-consuming and requires careful preparation to avoid common mistakes. Maintenance of poly-coated floors is relatively simple, but scratches and dents may require professional touch-ups. Polyurethane finishes can emit volatile organic compounds (VOCs), impacting indoor air quality.
Shellac – Shellac is a varnish made from the resin of the lac bug. It is a softer finish that is often recommended for lighter-colored woods. It is also better for areas with high moisture and frequent wear, as it dries much faster than polyurethane.
Under normal use and regular wear and tear, we can expect a lifespan of: 50+ years for building insulation. 25+ years for refrigerators. 20+ years for car bumpers.
Use a Roller on Large, Flat Surfaces
rollers lets you apply the poly fast and evenly. No brushstrokes, puddles or thin spots.
Polyurethane leaves a clear, glossy, or satin finish on the wood surface, which may have a slightly plastic-like feel. Look for a smooth, durable coating that resists moisture and scratches. If unsure, consult a professional or test a small inconspicuous area.
While painting over polyurethane is doable, it is a process that requires some time and effort. However, when done well, it can rejuvenate old-looking cabinets, furniture, and other surfaces.
Bubbles and streaks can ruin the smooth finish of your polyurethane floor. To avoid bubbles, make sure to stir the polyurethane gently and avoid shaking the can. When applying, use a high-quality brush or roller and apply thin, even coats.
Two coats of finish are suggested for most interior projects. When sealing floors, you should apply three coats. However, do not apply more than two coats in one day. 220 grit sandpaper should be used between coats to remove any air bubbles, but avoid using steel wool.
Coat the entirety of your workpiece, but don't brush excessively or you'll create areas with too little polyurethane. Allow each coat to dry fully. To give the subsequent poly layers something to bond to, sand lightly between coats with 320-grit sandpaper wrapped around a hard block.
For example, under normal wear and tear, a durability of more than 50 years can be expected for polyurethane insulation systems for buildings, more than 25 years for polyurethane used for insulation of refrigerators or more than 20 years for the application of polyurethane in vehicle bumpers.
Summary Comparison of Water based vs Oil Based Polyurethane:
water based: doesn't change color of wood, dries clear and stays clear. Ideal for light colored wood. oil based: darkens the color of wood adding yellowish tone, amber tone continues to darken over time.
Satin Polyurethane– A medium to low sheen finish, currently ranking as the most popular finishing choice among consumers because of its versatility and ease of maintenance. If you have recently been inside of a home with polyurethane flooring, there is a good chance it had a satin finish.
Matte. With a gloss level of < 5 units, matte sheens offer the lowest level of gloss and allow the wood to retain a natural look. Matte finish hides most substrates imperfections. For instance, most ceiling paint is matte in sheen as it hides installation, preparation, and finishing blemishes.
Wetting your brush before applying polyurethane is not necessary and can actually hinder the application process. Instead, ensure your brush is clean and dry before dipping it into the polyurethane.
A roller is the recommended method for applying some water-based polyurethanes, as well as some oil-based polyurethanes and moisture-cured poly finishes. Rollers are good for finishing multi-direction floors, like parquets.
Three to four coats of polyurethane are needed to waterproof wood. Water-based polyurethane will require several more coats than oil-based polyurethane.
Oil-Based Polyurethane: Wait 3 to 7 days before sleeping in the house. Water-Based Polyurethane: Wait 2 to 3 days before sleeping in the house. Natural Oils or Waxes: Wait 2 to 5 days depending on the specific product.