Wood Outdoor Furniture, Start to Finish
Jun 9th, 2010 by Kathy
When repairing a scratch, burn, or other injury to your wood outdoor furniture, you’ll want to re-finish it with the same type of finish with which it was originally finished. (And I’m just getting started with finishes!) If you applied the finish in the first place (and who doesn’t want to finish in first place?), you’ll know what kind it is. However, if you didn’t, and you don’t, you should find out, as each finish has different ingredients, and, therefore, different solvents.
While it can be difficult to distinguish one clear finish from another, you can usually recognize penetrating oil by its thinness and low luster. To identify others, dampen a rag with alcohol, and rub it on an inconspicuous area. If the finish softens, it’s probably shellac; if it doesn’t, try the same thing, using lacquer thinner, to determine if it’s lacquer-based. If neither test affects the finish, it’s likely to be varnish.
Of course, if you’re not fixing any damage, and you’re simply looking for the right finish for your new wood picnic table, Adirondack chair, ottoman, or porch glider, some popular choices include lacquer, shellac, polyurethane, penetrating oil, and acrylic and alkyd varnishes.
Lacquer, which is frequently used on commercial furniture, produces a thin, hard film, and is extremely resistant to wear and spills. You can spray it on, using professional equipment, or brush it on, as long as it’s the slow-drying kind; but don’t use it over other finishes. To remove it, use lacquer thinner.
Shellac creates a thin, radiant surface film, which will be clear or amber, depending upon whether you use the white, or the orange, type. You can brush it on in two or three thin coats, and take it off with denatured alcohol. Although shellac wears well, it can be ruined by certain spills; but, luckily, it’s easy to spot-repair.
On the other hand, polyurethane has superior resistance to spills and wear, but is hard to spot-repair. Apply two coats with a brush, but don’t use it over shellac. Polyurethane leaves a very hard, warm-toned film, which can be dissolved by turpentine or mineral spirits.
Penetrating oil will soak into the wood fibers, leaving a natural-looking finish; and tung oil is the most durable type. Apply at least two coats with a brush, let it stand for about half an hour, and then rub it vigorously. To remove it, use mineral oil.
Acrylic varnish, which is moderately resistant to wear and spills, can be dissolved by water, if it has not dried completely. Brush or spray on two or three coats (although it usually comes in spray cans), and it will produce a thin, hard film, with no amber tones.
If you’re using alkyd varnish, brush on two or three coats, sanding between each application. This will create a hard, warm-toned film, with moderate to good resistance to wear and spills. Also difficult to spot-repair, alkyd varnish will come off with mineral spirits.
One important thing to remember, no matter which type you choose, is that using too much finish can have disastrous results. If you want proof, just look at my opening paragraph!
Yours Outdoors,
Kathy






















