How to Choose a Wood Finish

The Forest Products Laboratory's division of finishes into film-forming and penetrating does most of the choosing. Films are easier to clean and better at resisting scratches, dents and stains, so they suit surfaces used and wiped every day; penetrating finishes leave the wood's texture, cannot peel and are simple to renew, but protect less. The families are explained in wood finish types.

A table is wiped, spilled on and leaned on daily, which is the case the Laboratory makes for a film. Choose a polyurethane labelled for interior furniture — the comparison of makers' figures is in choosing a polyurethane. Minwax also lists bar tops and kitchen countertops among the uses for its spar urethane. Lacquer and shellac are films too, faster-drying, covered in shellac and lacquer. For an opaque surface, see choosing paint; for a light, buffed finish over stain, choosing a wood wax.

A cutting surface is cut into, so a film on it will not last. The Forest Products Laboratory suggests mineral oil or paraffin wax for cutting boards and butcher blocks; General Finishes says the mineral oils in its Butcher Block Oil meet the requirements for wood that contacts food and that the product is maintenance, to be reapplied regularly. Food-contact claims are scoped to a product and a use — see food-safe wood finishes before choosing.

Outdoors, a film finish peels from wood the sun has already degraded unless it is sanded back, the Laboratory explains, and penetrating finishes need renewing far more often. Minwax formulates its spar urethane with ultraviolet absorbers for exterior wood and says even so that no clear exterior finish permanently protects wood and that it should be checked every year. For cedar, teak or pressure-treated wood used as decking or fencing, look for products made for those uses; they are outside this guide.

Every clear finish deepens the look of wood, and some add colour: General Finishes says its oil-based Arm-R-Seal brings out the beauty of walnut and mahogany and ambers over time. Wood also changes colour by itself — the Laboratory notes that dark woods tend to lighten and light woods darken with age, and that cherry takes exceptionally long to even out. Test the finish on an offcut; see a stain sample board.