Interior Wood Finishing Myths and Facts | |
Many do-it-yourself woodworkers view finishing as the least interesting, least challenging part of a woodworking project, and often rush through it in a simple process: sand, apply a stain, apply a finish. However, wood finishing requires thought and attention, and a simple mistake can quickly ruin a beautiful project. There are many wood-finishing misconceptions, but the experts behind the new Olympic Interior Wood Finishing System help debunk some of the common myths: Myth: Preparation of the wood before finishing is the only thing to worry about in obtaining a quality, high-gloss finish for your project. Preparation of the wood (refinishing, sanding, and conditioning) is extremely important in determining the finish of your final product - you simply will not be able to get a high-gloss finish if you botch the preparation stage. However, equally important is how much attention you pay to rubbing and polishing the finish with a furniture polishing compound after application. You should let the finish "cure" for at least a month before beginning the rubbing and polishing process. Myth: Furniture refinishers not only strip wood, but also condition it. This is an illusion brought on by the mineral oil contained in many refinishers. The mineral oil remains in the wood longer than the other ingredients and makes the wood appear moist and conditioned. However, the mineral oil has no beneficial effects on the wood, and it can actually weaken the bond of water-based finishes to the wood. That's why it is a good idea to use a wood conditioner before staining soft wood such as spruce, pine, and fir. A good wood conditioner ensures smooth, even stain penetration and helps to seal the wood. This reduces expansion and contraction of the wood during humidity changes. Myth: Steel wool can always be used in place of sandpaper when refinishing. Although steel wool is an excellent tool when refinishing wood projects, it should never be used when working with any water-based finishes. If even a small bit of the steel wool breaks off on the wood and is covered by a water-based finish, it will rust and mar your finish. Always stick to sandpaper when you use water-based finishes. Myth: When refinishing, you must sand with at least 400-grit paper. Although it is important to begin with a rougher sandpaper (80-100 grit), and finish with a fine sandpaper, you do not really have to go beyond 220 grit. Sanding with any higher-grit paper will not make much of a difference after the finish is applied, and will take up a lot more of your time. Myth: Some "advanced" water-based stains will not raise the grain of the wood. No matter what they claim, all water-based stains and polyurethane topcoats will raise the grain of the wood to which they are applied. However, there is a simple trick that will minimize this problem: after the initial sanding, use a sponge to moisten the wood, and then let the wood dry. This will raise the grain. Then sand the wood with 200 grit or finer sandpaper and clean off the dust. When applying the stain or polyurethane, lightly sand between coats with a fine grit paper. Myth: Anytime you are using stain on wood, you must apply "with the grain." Although you should always apply varnish with the grain, do not worry too much about applying or wiping off stain with the grain of wood. The important thing to remember is to wipe off the excess stain and make a "finishing stroke" with the grain at the end of the staining process. This technique should hide any streaks that you might leave. Myth: Water can damage water-based polyurethanes. Many people think that water-based finishes are susceptible to water damage. The resins used in these products, once thoroughly dried and cured, cannot be washed off or dissolved with water. In this respect, water-based polyurethane is just as strong as oil-based polyurethane finishes. Myth: The more coats of oil-based polyurethane you apply, the glossier the project will be. It's important to apply at least two or three coats of any finish to wood for initial penetration and protection but, after that, the number of coats of finish will not make a difference in the level of gloss. A high sheen and true protection can only be obtained by applying rubbing compounds, paste wax, or furniture polish. Remember to let your finish cure for at least a month before rubbing and polishing your project. Myth: To increase penetration of an oil-based finish into wood, rub it in. Aggressively rubbing an oil-based finish into wood is not a good idea, and it does not increase penetration. Rubbing causes friction, which causes heat, which seals the wood pores and actually prevents further penetration - the exact opposite of what you're trying to attain. The best way to increase penetration of a finish is to keep the wood surface wet, but increased penetration is overrated. It does very little to protect the wood. Written by Amy Z. Leathers. She is a technical manager, specialty wood coatings, for Olympic Stain. For more information, call (800) 441-9695. Reprinted with permission HouseNet, Inc. |