Putting the Finishing Touches on Your Wood

by DoItYourself Staff

Wood Stain

Is available in oil-based, water-based and gel formulations.

The two major types of wood stains are semi-transparent and solid-color (opaque), where the essential difference between the two is that semi-transparent stains impart color, but the texture and the natural grain of the wood continues to show through; while on solid-color stains, the texture still shows through, but not the grain itself.

Interior stains, used for furniture and woodwork, come in either pigmented or dye categories. Both can have oil, synthetic or water bases. Pigmented stains color the wood with the same type of pigments used in paint. They range in color from almost clear to semi-transparent. They are easy to apply—usually brushed on or wiped on with a rag, then wiped off enough to control the depth of the stain. They leave no brush or lap marks if applied properly

Exterior stain is used primarily on wood siding and shingles, decks, outdoor structures and furniture. It is also available in latex and oil-based formulas. Oil-based stains penetrate the wood, and they erode with weathering. Latex stains do not typically fade as rapidly.

Stains may or may not protect the wood; check manufacturers’ labels. An oil or polyurethane finish can be mixed with the stain, so the do-it-yourselfer can complete the staining and finishing job in one step.

Wood stain pens will hide minor scratches, nicks and chips on furniture and wood.

Varnish

Is a blend of oils and resins that coat the surface of wood to give it a transparent, protective coating, allowing the beauty of the wood to show through.

It can leave a gloss, semi-gloss or satin finish, depending on its formulation.

Varnishes fall into three groups, divided by their base: alkyd, latex or phenolic.

Phenolic varnishes of modified phenolic oils deliver the best durability, especially in exterior uses. They absorb ultraviolet light and neutralize oxidation. However, they also tend to yellow faster than other varnishes.

Alkyd varnishes offer flexibility and hardness in both interior and exterior uses, but in exterior use they oxidize more quickly. However, they do not yellow as much as phenolics.

Latex varnishes offer the advantages of oil-based coatings and the cleanup convenience of a water based coating. The acrylic coatings take from 30 to 90 minutes to dry and do not yellow the wood. Some acrylic-based varnishes are even durable enough for use on floors; check manufacturers’ recommendations.

Varnishes are also typically mixed with a tung oil or linseed oil.

Polyurethane

Comes in water-based and oil-based formulations.

Recommended for interior use on floors and many times wood furniture because of its excellent protection.

Polyurethane stains are better used for interior applications for water-resistance and hard use, but customers may object to the plastic appearance they produce. Alkyds offer a more natural-looking gloss for furniture and indoor architectural trim and doors.

It is generally not recommended for outdoor use because it will yellow and crack when exposed to ultraviolet light—unless ultraviolet light absorbers are added

Shellac

Provides a fast, hard-drying, durable finish for furniture, woodwork, hardwood floors and other wood-finishing applications.

It also functions as a sealer and stain-killer on drywall, cured plaster and new wood. Shellac is widely compatible with other coatings, and it can be applied over old shellac, varnish or lacquer finishes that are adhering well.

Most shellac is sold in a 3-lb. cut, the consistency recommended for most uses. The 3-lb. cut can be thinned to a 1-lb. cut for applications such as wood sealer before staining by thinning one quart of shellac with three pints of alcohol.

For applications where water spotting may be a problem, shellacked surfaces can be protected with paste wax or varnish.

Shellac may be applied with a brush, foam brush or from a can. Advise customers when brushing to flow on the shellac from a full brush—with minimum brushing—and not to re-brush areas, since the alcohol-based solvent of shellac dries quickly.

Cleans up with ammonia and warm water

Wood Preservatives/Waterproofers

Water repellents minimize water damage on pressure-treated and untreated wood. Some also contain a mildewcide to control mold and mildew. Use water repellent formulated for immediate application to pressure-treated wood to avoid premature cracking, splitting, splintering and warping. Periodic re-applications help prevent water damage as wood ages.

Wood preservatives by themselves provide no protection against moisture or water. Water repellency must be formulated into the product. Mildewcides are also frequently formulated into preservatives.

Water-borne, water-repellent preservatives for wood offer lower environmental hazards and convenient water cleanup. They provide an alternative to conventional solvent-based, water-repellent preservatives while retaining effectiveness, rapid drying qualities and excellent paintability.

Wood toners are water repellents that add color to highlight wood grain. Although toners are not to be used as if they are stains, adding color to a water repellent gives wood the benefit of ultraviolet light protection.

Most toners on the market are designed for use on pressure-treated wood. Some repellents contain ingredients that cause water to bead.

Specialty waterproofers include a multi-surface formula that can be used on brick and concrete, an aerosol version that works well for small exterior projects, a fence protector, a leather and fabric protector and a sport waterproofer specially designed for use on outdoor fabric and sporting equipment.

Preservatives should be reapplied periodically

Lacquer

Is available in clear or colored formulations and has a fast-drying finish.

Customers should be advised to work fast with lacquers. Also suggest a 50/50 mixture of lacquer and lacquer thinner (each preferably made by the same manufacturer).

Lacquers should be applied only to new wood or over previously lacquered surfaces. They cannot be used over old paint or varnish; the solvents will lift old finishes.

Lacquers are available in clear or colors. They are usually difficult to apply by brush. However, some manufacturers do offer specially formulated versions that apply more easily with a brush.

Lacquer thinners are required to clean tools

Oil Finish

Common types include Danish oil, tung oil or Swedish oil.

Provides coloring and protection in one step. However, oil finishes do not stand up to alcohol or water the way polyurethane does, so they are not recommended for high-traffic, abuse-prone applications.

Oils make nice, low-luster finish for furniture and other fine pieces. Waxing can provide water resistance with these finishes.

Lemon oil can be used to replenish fine wood with its natural oils while protecting the finish. It is best to use products that contain no beeswax or silicones that could cause a buildup or darken the wood.

Timber oil is a wood finish designed to penetrate exotic hardwoods such as mahogany and teak. This specialty wood finish helps preserve the hardwood and maintain its natural appearance.

Available in several shades, timber oil is a combination of tung oil, linseed oil and long-oil alkyds. In general, teak should be treated with oil-based formulas. Since teak is denser than many other common woods, wood protector should be applied with a brush or by rubbing it in with a cotton cloth.

Wood Hardener

Formulated to strengthen and reinforce decayed or rotting wood.

Is a liquid consolidating agent that seeps deep into soft, deteriorated wood fibers, then hardens it to restore strength and some structural integrity.

Depending on the strength required, the formula can be water-based, solvent-based or two-part epoxy

Grain Filler

Fills the open grain and pores on hardwoods like oak, ash and mahogany.

Designed to achieve a flat surface on work surface before top coating with a clear finish.

Paste Wax

Protects and adds luster to any stained or finished wood surface.

Many formulations contain carnauba for enhanced durability.

Commonly used on hardwood floors and fine wood furniture and even marble surfaces.

Dries quickly and doesn’t cause surface to become slippery.

Wood Conditioner/Sealer

Is used on softwoods to help tame wild grain patterns and to even up stain absorbency.

The sealer penetrates the wood, which allows a more even color appearance and grain pattern

Linseed Oil

Pure preservative available in boiled and raw formulations.

Boiled linseed oil has driers added to promote faster drying than raw linseed oil.

Offers superior penetration into wood surfaces and provides good UV protection.

Also improves the flow and gloss of exterior oil-based paint.

A classic finish for natural wood to seal and protect it

Wood Finishes Safety Tips

Always wear safety goggles and protective gloves, and make sure there is adequate ventilation where you are working when using wood finishing products.

Lacquers should be handled with extreme caution. Fumes are noxious—especially dangerous to the user in a closed room. In addition, fire and explosion hazards are much greater than with ordinary paints and varnishes.

Never pour leftover wood finishing chemicals down the drain or on the ground. They should be disposed of according to local regulations. You might even consider donating them to a local craft group or other organization that might make good use of the product.

Rags used to apply wood finishing products should be disposed of properly to avoid spontaneous combustion. Always soak rags used to apply or clean up wood finishing products in water, and them store them in a sealed metal container before disposing of them according to local regulations.

Always read the label carefully for wood finishing products and use the product specifically how the manufacturer states.

Never work in an area where there is the possibility of sparks or where an open flame is present.

Always seal containers properly after each use then store products where they can’t be reached by children.