In order to protect wood from weather damage, you need to apply a wood finish. This will keep the color and wood intact. If the wood is not finished correctly, it will peel and the wood will be damaged. Preventing damage is easy to do with a good finishing job.
It is daunting, however, to go into a hardware store and see all the different choices for clear wood finishes. Luckily, they fall into only a few categories with clear differences. The main options are rubbing oils like Tung oil, slow drying finishes including varnish and polyurethane, and fast-drying lacquers. Each option has different advantages and disadvantages to be considered.
Tung Oil Finish
Oils like Tung oil are some of the easiest wood finishes to work with and offer terrific results. Oil finishes are often used with unfinished wood, but can go over an oil-based stain as well. However, wood must be sanded smooth, since Tung oil does not produce a sandable film.
The first coat is often thinned using turpentine to better penetrate the wood. This makes the wood dry more quickly with better results. To apply the oil, dip a cloth or rag into the finish and rub it onto the wood until it is saturated. Brushes with natural bristles should be used for places that are hard to reach.
After 20 to 30 minutes, the coat should be wiped down to remove any excess finish, drips, or runs. Then a new coat can be applied. Three to four coats are typical.
The oil then needs a day or two to dry. This quickly protects the wood under the finish. If applied on a yearly basis, Tung oil is a good finish for outdoor furniture. It also works well for interior refinishing applications.
Varnish or Polyurethane Finish
Varnish and polyurethane provide more protection but are more difficult to apply than Tung oil. Varnish is especially useful for exterior doors that are exposed to rain. Apply to the wood after it has been lightly sanded.
Always start with gloss varnish for the first layer. Apply using a bristle or ox-hair brush, going from dry to wet.
Varnish dries quickly, so it will be clear what has been painted. This takes 24 hours to dry and should then be repeated with gloss, semi-gloss or satin varnish, depending on the final look you desire. This creates a distinctive look for the wood.
The type of varnish determines whether the varnish will hold up well in exterior conditions. For areas where you expect high water exposure, spar varnish is a good choice. It is the same varnish used in marine applications.
Lacquer Finish
Lacquer is the hardest finish to apply but creates the most pleasant look. A good lacquer is also the strongest; even with lacquer thinner, the lacquer only dissolves and if it is allowed to dry, it will dry again into a film. This creates a finish that many people highly prize. However, because it dries so quickly, it is very hard to apply.
After sanding the wood and cleaning it, lacquer can be sprayed in overlapping horizontal stripes onto the wood from a distance of about 16-18 inches. This will create a great look for your cabinets or furniture.
Lacquer isn’t recommended for outdoor use.
Finishes protect wood and make it look better. Using a good wood finish will not only transform the look of wood but will also protect it. Oils, varnishes including polyurethane and lacquers all work for finishing all types of wood. The right option is determined by the condition the wood will be exposed to and your skills.