How To Finish Wood 101: A Wood Finishing Guide
Time Required: Under 2 hours
Applying a wood finish is an essential step to protect the wood's surface. Finishing wood prevents swelling and cracking, protects against stains and enhances the appearance of the wood. This guide will show the different types of wood finishes, how to select the right types of wood finishes and how to finish wood.
The main reason to apply a finish to wood is for protection. Wood is a porous material that will absorb moisture, dirt and oils. Protecting your wood projects with a finish will keep it looking good for years to come. Also, finishes improve wood's appearance. Stains highlight and add color to wood grain and finishes seal in the color, increasing its longevity. Even basic clear finishes add sheen and warmth to wood.
There are several types of interior wood finishes. Each finish offers a different level of protection and appearance on the surface of wood. Depending on the project, you can use more than one finish. Wood finishes fall into two categories: penetrating finishes and surface finishes.
Polyurethane wood finish is a liquid plastic that provides a durable finish when it cures. It comes in several clear finishes: gloss, semi-gloss, satin and matte. It's also available in oil- and water-based formulas. The water-based poly finish is known as polyacrylic and is more popular due to its ease of use and cleanup. You can apply polyurethane with a synthetic or natural brush, rag, roller or with a sprayer. Polyurethane is a good all-around finish that can be used for almost any type of indoor wood projects.
Shellac finishes are traditional, but are not often used anymore. Shellac is a natural product made from combining a resin secretion from the female lac bug with a solvent (alcohol). Shellac adds a protective coat to surfaces while giving wood a warm amber glow. It's heat sensitive and is not recommended for tabletops. Shellac can be applied with a natural bristle brush or cotton rag.
Lacquers dry to a hard and durable intense gloss finish. Lacquers dry much quicker than oils, so finishing can be done more rapidly. It is an extremely durable finish that's resistant to damage. However, over time it can begin to discolor and become scratched. Lacquer is best applied with a spray for an ultra-smooth finish.
With the popularity of chalk and milk paint, paste wax is becoming a popular way to finish wood. Paste waxes are usually made from Carnauba wax. It does not offer protection from heat, but it protects the wood from moisture. When applied properly, paste wax can add beauty to an old piece of furniture. Apply paste wax with a cotton rag.
Interior wood stain is used to accentuate the grain in natural woods or plywood while still adding some color. While wood stains offer some level of protection on wood, it's recommended to use stain in combination with a surface finish. Stain can be applied with a brush or cotton rag.
Varnish is a type of clear finish that is composed of a solvent, resin and oil. Traditional varnish is based on natural resins and oils and is thinned with mineral spirits or turpentine. They are available in satin, gloss and semi-gloss finishes. Varnish is translucent, which allows the natural characteristics of a piece of wood shine. Varnish also adds a barrier that protects the wood against damage, including scratches and dents. Varnish can be removed by using a small amount of lacquer thinner and some sandpaper and then reapplied for a fresh, new appearance. Apply varnish with a new, natural-bristle brush.
Wood oils are penetrating finishes that are easier to apply and leave a more natural look. They are applied heavily then wiped down to a dull sheen. Oils do not provide a shiny surface and may feel sticky for some time. Wood oils should be applied with a rag for the best results. Here are a few options for oil finishes:
- Lindseed oil is made from flax seeds and is slow-drying with good preservative properties and water resistance.
- Danish oil is a penetrating linseed oil finish that is polymerized for fast and easy application.
- Teak oil does not exist as a product made from an actual the teak tree. It is named “teak oil” because it is marketed to be used on teak wood. Teak oil is usually based on a mixture of linseed oil, varnish and mineral spirits. It is commonly used as a finish for outdoor furniture.
- Tung oil is often used as a drying oil and mixed with other varnishes and oils. Pure tung oil hardens upon exposure to air, so the resulting coating is transparent with a deep, almost wet look.
- Mineral oil for wood or Butcher block oil is an inexpensive and popular choice for wooden kitchen surfaces. Use mineral oil for wooden cutting boards and butcher block countertops. It is non-toxic, fills pores in wooden surfaces and repels food and liquids from entering the wood.
- Cedar oil rejuvenates the wood while infusing the wood with a natural insect repellent quality. It's derived from aromatic red cedar and can be used on any type of wood.
- Ipe oil is used to finish and protect decks made from exotic hardwoods for a deep natural wood finish. Ipe oil is not for use on interior wood.
- Prepare surface of the wood by sanding to smooth down scratches or snags.
- Sand with the grain of the wood. Use a coarse 120-grit sandpaper if there are deep gouges or imperfections in the wood.
- Repeat the sanding process with a progressively finer grit sandpaper until you are satisfied with the surface of the wood.
- Wipe down the surface with a clean cloth or tack cloth to remove dust and other excess materials.
- Pick the finish want for your wood.
- Stir the finish in the can before applying it.
- Apply the finish onto your wood as thinly as possible with a natural bristle brush or rag.
- You may need to apply several coats of finish to your wood. Allow the first coat to completely dry before you add the second coat.
- If needed, lightly sand between coats to eliminate bumps and other imperfections before adding more coats.
- Wipe off the dust with a tack rag before applying the second coat.
- If adding a third layer of finish or more, be sure to sand and clean off saw dust in between coats.
- Once the finish is completely dry, wipe the entire surface down to remove any lingering particles.
Keep your woodworking projects looking their best with an attractive finish. Visit your local The Home Depot to get everything you need for finishing wood.