The Best Wood Finish for Exposure to Water & Soil

Types of Finish

• Wax, oils, shellac, varnish and paint are typical wood finishes. Wax and oils are more porous to water and soil than the other finishes are. Tung oil is water-resistant, but linseed oil is not. Wax provides protection from soil and grime, but you must reapply it regularly. Buffed shellac finishes are somewhat water-resistant. Polyurethane varnish and paint provide the best, most durable finish to resist soil and water.

Polyurethane Varnish

• Polyurethane varnish provides good protection but also contains toxic petroleum-based chemicals. Water-based polyurethane finish uses fewer volatile organic compounds, or VOCs, and is safer than oil-based polyurethane. Toxic chemical compound levels are higher immediately following application. The use of pure oil, wax and shellac finishes has increased in recent decades in response to awareness of VOC toxicity in homes.

Shellac

• Shellac is a nontoxic wood finish that provides some protection from soil and water. It is a natural resin secreted by an insect found in India and Thailand. To apply shellac, rub on successive thin layers that build the surface to a high polish. It is nontoxic when the solvents evaporate. It is often used as a wood sealer before adding more durable finishes.

Wax and Oil

• Furniture wax is easy to apply and has low toxicity. It provides short-term protection from soil and water. Furniture surfaces are usually lightly sanded or brushed with steel wool #0000 to create a “tooth” to which the wax or oil can adhere. Tung oil and linseed oil are absorbed by wood and require several coats. Linseed oil darkens with age and is not as water-resistant as tung oil.