It's fairly obvious when a favorite piece of wood furniture needs attention. Food stains and water marks blemish a handsome table; after years of faithful applications, spray-on polishes leave a dark, sticky film on sideboards and chairs. "Once you can no longer appreciate the beauty of the wood, it's time for a cleaning," says Eli Rios, proprietor of ECR Antique Conservation and Restoration in New York City.
Cleaning fine wood furniture can be downright dangerous to the furniture's finish if the wrong methods are used. The key is to start with the gentlest cleansers, working up to stronger solutions as necessary, and to test on discreet areas, such as the inside of a table leg, before tackling large expanses.
First, try a simple cleanser: Dampen a cotton swab with water, add a drop of dish-washing liquid, and test. If the finish survives, make a solution of water and detergent, and wipe the entire piece. Don't saturate the wood; keep the sponge barely damp, and rinse often. The results can be dramatic. Eli also uses mineral spirits, a clean cloth, and confident, circular strokes to remove decades of grime.
Wood that remains grubby-looking after the mineral-spirits treatment needs some degree of refinishing. Try rubbing denatured alcohol on a small, hidden area. If the finish does not dissolve, it's oil, lacquer, polyurethane, or varnish, all of which require professional treatment. If it does dissolve, the finish is shellac. The top layers should be removed and replaced with more of the same, a task that may also call for a professional.
Once it's been cleaned -- by whatever method -- wood must be protected. Eli shields wood finishes with wax, applied swiftly and liberally with cheesecloth. Before waxing, he lightly rubs the wood with fine steel wool, which gently roughs up the surface so that the wax can go on evenly. Professionals call this mild abrasion "tooth." For most furniture, Eli uses conventional butcher's wax, made from beeswax. On more fragile finishes, he applies costlier acid-free microcrystalline wax, such as Regency, which doesn't smudge easily and is more heat resistant than butcher's wax. He also recommends dusting wood furniture with a soft cloth, never a feather duster. "It doesn't do much good and can lift bits of veneer," he says.