Choose a humidity-fighting finish for bathrooms
What finish would best protect the front and sides of a bathroom vanity and medicine cabinet?
—Stacey Martin, Kennewick, Wash.
Your vanity and medicine cabinet will have to endure occasional water splashes and high humidity, Stacey. Polyurethane resists moisture damage, plus it survives light abrasion better than the alternatives. That also makes it hard to repair. Lacquer is easy to repair, but offers less protection from water and chemicals, and water-based finishes are difficult to repair and susceptible to such chemicals as ammonia-based glass cleaners.
One thing to consider about polyurethane: It adds an amber color that you may not want if you're using light-color woods such as maple. An alkyd-resin varnish, such as McCloskey Heirloom or Pratt & Lambert 38, dries slightly clearer and is easier to rub out, although that also makes it less abrasion-resistant. Whichever you choose, apply at least three full-strength coats inside and out for the moisture protection that bathroom projects require.