If flight holes are observed in furniture, it is important to determine if the infestation is active. Active flight holes are light-colored and contain a fine, sawdust-like material called frass. Any material resembling sawdust that appears on the floor underneath a piece of furniture could be a sign of a possible infestation. Frass from an infestation that is no longer active can be dislodged if furniture is moved or jostled, giving an impression of insect activity, but should frass continue to appear after being swept away, it is likely that the infestation is active. If furniture or other wooden objects appear to have active infestation, they should be isolated immediately by placing in a large sealed plastic bag. As fumigation may be the next step, and there are a variety of methods available to accomplish this end, a conservator or exterminator who is familiar with conservation issues should be called immediately.

Housekeeping

It was once thought that furniture needed to be "fed" with various mixtures of oils and other materials to keep it from drying out. These mixtures enhance the appearance of wood temporarily, but ultimately do not keep wood from drying out. No amount of oil will prevent furniture from drying out if the RH remains below 30% for a period of time. A better approach would be to keep furniture in a stable environment. Furniture oils are not recommended for maintenance as many of them contain linseed oil or other drying oils, and when used repeatedly will create a gummy, insoluble surface coating that darkens and obscures the grain of the wood. Other furniture polishes contain non-drying oils such as lemon oil and although they do not harden or darken, they nevertheless attract and entrap dirt and grime. Silicone polishes are also not recommended as they leave a film that is difficult to remove and can interfere with future finish treatments.

The best maintenance for clear varnished furniture is a coating of good paste wax. Wax is a very stable material that does not change chemically over time and provides protection from moisture and airborne pollutants. Good quality paste wax is available in most hardware stores. A thin coat applied following the directions on the can is all that is needed, no more than once a year. It may not be appropriate to wax furniture that is gilded, painted or lacquered, or furniture that has unstable veneers or flaking finish. Consult a conservator if any question about the appropriateness of waxing arises.

Once a protective coat of wax has been applied, dry dusting with a soft cloth is recommended for routine cleaning. Dust and dirt are harmful to finished surfaces and should be regularly removed as they can scratch or otherwise damage polished surfaces. A soft cotton cloth or artist`s brush is best for dusting. Feather dusters are not recommended for dusting as the feathers tend to get caught in cracks and crevices and can cause detachment of fragile veneers and gilding. A clean cloth slightly dampened in water may help to remove more stubborn dirt. When dusting, be cautious in areas with loose elements such as veneers, moldings, and metal mounts. Should an element become detached, place it in a plastic bag labeled with its original location on the piece and place it in a drawer or other accessible location until a conservator can reattach it.

If brass hardware on furniture is tarnishing, the owner may want to polish it. In most cases furniture hardware was intended to be brightly polished. Hardware was often given a protective coating of lacquer at the time of manufacture to retain its highly polished appearance. Over time, the coating wears off and the brass underneath is exposed to the air. Although some owners prefer lightly tarnished hardware on an old piece, others who prefer bright gleaming hardware may embark on a regimen of regular polishing. There are many brass polishes on the market. Those that contain ammonia can cause long-term corrosion problems, so it is best to choose one of the polishes that has a mild abrasive embedded in cotton wadding. Ideally, hardware should be removed for cleaning so that the polish cannot come into contact with the surrounding wood. If that is not possible or practical, polish the hardware carefully, confining it to the metal only. A good option to a regular regimen of hardware polishing is to have the hardware coated with clear lacquer.