Jul
Once you have completed the construction of a piece of furniture, you should decide on the type of finish you will give the wood. The most suitable finish depends on two considerations: how tough a surface you want and the type of wood you are using.
Before applying your selected finish to an entire project, try it out on the underside or on a scrap of the same type of wood. You’ll often have to experiment with finishes in order to achieve a uniformly rich appearance over the entire project since many of those shown are made from a combination of woods.
Protective Finishes
Furniture wood must be protected. It is too easily soiled or damage if left in its natural state. Wax, shellac, lacquer, varnish, penetrating resin, and oil are all transparent protective finishes that help preserve the natural color of wood.
Waxing.
Wax gives a soft, lustrous gloss but it protects wood only from dirt discoloration. First, apply a thinned coat of shellac or resin sealer. Then sand lightly and follow with at least three coats of paste wax, buffed after each application.
Shellac.
Shellac gives a hard, gloss surface, but doesn’t provide a very durable coating. For this reason, it’s not recommended for furniture that will be subjected to hard wear. It is a fine finish for giving richness to many medium and dark cabinet woods.
Its lack of durability calls for frequent retouching with alcohol or new shellac. It is soluble in many common household liquids – including thinners, alcohol, ammonia, soaps, detergents, even hard water. Don’t use shellac on teak, ebony, or cedar; it’s not compatible with these woods.
Purchase shellac fresh – it deteriorates in storage. To use it, thin two parts liquid shellac with one part denatured alcohol.
First smooth the wood. Both staining and filling the wood are optional but often desirable. Then use a fully-loaded brush to apply shellac with a slow, smooth-flowing motion (overlapping adjoining strokes) to develop a clean, even film.
Allow the first coat to dry for 1 or 2 hours, sand with 180to 220-grit abrasive, and follow same procedures for second and third coats. If you plan to wax the surface, wait 24 hours after the last application. Then apply hard paste wax, and buff.
Lacquer.
Speedy application and good surface protection are characteristic of lacquer. Most lacquers dry fast enough to be impervious to dust in 3 minutes.
There are types available for both spraying and brushing. Brush types have a retardant to keep them from drying too fast. When using brush lacquer, you must wait for each coat to dry. Each new coat softens the one beneath; therefore work fast, keep the brush loaded, and draw it over the surface only once. Always brush with the wood grain. Final sanding and rubbing will smooth out rough spots.
If you spray, use the spray gun like a brush, working the length or width of the surface with each stroke. Hold the gun 6 to 10 inches from working surface; draw it slowly back and forth in even paths. Permit a slight overlap. Spray legs and sides first.
Five or six sprayed coats are adequate – any more may crack. Allow four hours drying time between coats, let surface dry for 48 hours, rub with 4/0 steel wool, then apply remaining coats. Allow to dry for another 48 hours, and then give it a final sanding and rubbing.
Varnish.
The most durable and protective of all clear, on-the-surface finishes, modern varnishes produce a tough finish that is heat, abrasion, impact, chemical, alcohol, and water resistant.
Most are synthetics – they can be chemically tailored to specific jobs. Also, they are easier to apply, longer lasting, and produce better surfaces than the older natural oil-resin finishes.
Simply apply evenly on a clean surface, and let dry thoroughly before re coating. Varnishes usually require a long drying time – dust is a real problem. So close all windows and apply varnish in a dust-free room. Scuff carefully between coats with 4/0 steel wool and rub the final coat with FF F pumice sprinkled on a thin layer of rubbing oil, using a felt pad. Remove stray dust particles with a silver of wood.
A day or two after the final rub, you can apply a hard paste wax to the surface to preserve the glossy finish.
Penetrating resin.
This type of finish ideal for many furniture projects. Wood grain and figure are enhanced by a slight darkening, yet the wood does not appear to be under glass. It is easy to apply, fast drying, tough, and resilient. No filler is required when using penetrating resin – the finish soaks into the surface of the wood, using the wood structure as fibrous filler.
Apply enough of the resin to keep a clean surface wet for at least half an hour. At the end of this wet (or soak) period, wipe the surface clear with a lint-free cloth. Second and third soaks, if they can absorbed by the wood, will make a harder surface. To repair a scratched or marred surface, merely apply more resin to the blemishes.
Oiling.
Boiled linseed oil, properly applied, will not only seal wood but provide a durable finish. Apply in thin coats while warm, allowing each coat to dry for 48 hours and rubbing with fine sandpaper between coats. Professionals use 6 to 12 coats.
Newer Danish oils are wiped on with a rag quite easily. Spread a generous coat on the wood, let it stand 1 hour, wipe off the excess, and let dry overnight.
