Saving and Protecting Original Finishes

Every clear finish has two purposes: to protect and enhance the beauty of the wood.

Our job is to make sure the finish is up to the task.

Inside our homes we are apt to find a variety of different types of finishes, most of which look similar, if not identical. When a finish is still in the can, we can often determine which type it is just by the odor of its solvent: mineral spirits for oil-based finishes, water for water-based, lacquer thinner for lacquer, and denatured alcohol for shellac.

Once dry, however, the solvent has evaporated and the protective resins left behind on the wood often look, feel and smell the same.

While professional restorers will go to great lengths to analyze and determine exactly what type of finish is on any piece of Arts & Crafts furniture, we won’t need to, for our goal is simply to save and protect any original finish.

Most Arts & Crafts furniture was originally finished with either shellac or an early form of lacquer. Both of these finishes are vulnerable to water and heat, so they often were topcoated with a layer of paste wax. But paste wax is also a weak finish and wears away over time, leaving the original shellac or lacquer - and the wood - exposed.

The best solution is to apply an additional coat of paste wax, for both museum curators and collectors recognize and recommend paste wax as an acceptable preservative for an original finish. What is not accepted is an additional coat of shellac, lacquer or varnish, including linseed oil, tung oil, Danish oil, teak oil or any other mineral spirits-based penetrating finish (if it contains mineral spirits, it’s considered an oil-based varnish).

While these modern finishes do protect the wood, they permanently obscure and alter the appearance of the original finish – and decrease the value of the antique. Paste wax, however, is acceptable, for unlike these other finishes, paste wax can be removed with mineral spirits without also removing the original finish beneath it.

Not all waxes are created equal, however. The best waxes contain a high level of carnauba wax. Harvested from the leaves of the carnauba palm tree found only in Brazil, carnauba wax is extremely hard and is typically blended with softer beeswax to make it pliable.

Liquid and semi-paste waxes with little or no carnauba wax may be easier to apply, but they wear off quickly. Furniture polishes, aerosol sprays and dusting oils are even worse, for their instant luster give us the false impression they are protecting the wood. You may have to look hard to find it, but true paste wax is the best.

The greatest damage to an original finish is often done under the pretext of first ‘cleaning’ it. Strong cleansers often contain solvents and chemicals, such as ammonia or trisodium phosphate (TSP), that will soften, damage and dissolve an original shellac, lacquer or wax finish.

Just as you would not sand out every little scratch in a fine antique, you should not attempt to remove every speck of dirt. Wiping off dust and washing off food with a damp cloth is one thing; attempting to scrub off a century of rubbed-in sweat, oil and wax will only result in removing the original finish along with it.

Before waxing I simply use a damp cloth to wipe off any surface dirt, followed immediately with a clean, soft, dry cloth. If the grime is deeply imbedded into the finish or even the pores of the wood, it stays. Better to error on the side of caution than to suddenly discover you have erased a hundred years of mellow patina with a few swipes of a scrubbing pad.

Apply your paste wax with a soft cloth, let it almost harden, then buff off the excess with a clean, fresh, soft cloth. While I apply the wax in a circular motion, I always buff in the direction of the grain of the wood to avoid leaving any swirling marks from my cloth in the dried wax.

Finally, keep in mind that paste wax is still a relatively weak finish. Do not place plants or vases containing water on it, for the condensation can seep through the wax and damage the finish. Make sure any pottery you set on it does not have rough edges. Use place mats under dinnerware and serving dishes. Keep hot pans where they belong – on the stove. And decorate with Arts & Crafts table runners and drink coasters.

How often should you wax?

Sometimes once is enough, such as on the vertical sides of bookcases, china cabinets and sideboards. Table tops that get heavy use, especially if they may have drink glasses set on them, get a fresh (but thin) application every year or two.

-bj

Coming Next: Cures For a Wet Basement