Types of Finish
Before going about restoring a wood finish, determine what sort of finish it is. There are four finishes that are used on wood. Shellac finish is more common in furniture that was made before 1920. Lacquer finish is typically used on commercially made furniture because it tends to dry fast. Varnish finish is more associated with custom-made furniture. Penetrating oil is a form of finish that is not easy to recondition since it typically penetrates the wood.
Testing the Finish
Denatured alcohol can help determine what sort of finish the wood has. You can test a part of the wood furniture that people don’t typically notice, such as the back of a chair’s leg. Dip a piece of work cloth into the denatured alcohol, then rub the cloth into the part of the wooden furniture that you choose for testing.
Determining the Finish
A shellac finish tends to become becomes soft on testing with denatured alcohol. If the finish turns white rather than softening, this is more typical of a lacquer finish. You can test further for lacquer by using a thinner. If the finishing then softens, you can be sure that it is indeed lacquer. If the finish does not soften with either the alcohol or the thinner, it is likely a varnish or penetrating oil finish.
Restoring the Wood
If you determine that the furniture's finishing is shellac, you can use denatured alcohol to restore the wood. In case the finish has lost its gloss but is not quite cracked, you can dip steel wool into the denatured alcohol, remove the excess alcohol then rub it into the wood. Rub the wood using a light stroke. You should work fast; otherwise, the finish tends to get soft and sticky. If the original finish is actually cracked, rub in the denatured alcohol using a brush.