Identifying Finishes for Repair
How can I identify the finish on a piece of furniture so that I can repair it?
Jack Simpson, Abilene, TX
To know which finish you’re dealing with, try to dissolve it. Test a hidden spot. You’ll know the finish by which solvent removes it.
First, remove any wax on the surface by rubbing it with a cotton cloth dampened with mineral spirits.
Next, in an inconspicuous spot, place a drop of denatured alcohol on the surface, wait a few minutes, and then rub the area with a paper tissue. If the finish is shellac, you’ll rub some off. If the surface stays hard, repeat the test with a drop of lacquer thinner. If the surface becomes sticky, the finish is lacquer or a water-based finish. The latter was rarely used before the 1990s, so lacquer is the only candidate on older pieces.