How do you repair oil-damaged finish?
Q:
Without noticing, I spilled a few drops of home fragrance oil on our hall table. When my husband wiped up the oil the next morning, it lifted the finish down to bare wood. Please explain why this happened and how to fix it.
—Aprile Kohler, Des Moines, Iowa
A:
The oil contains solvents that reacted with the table's finish, which was probably a type of lacquer, Aprile. Unlike varnish, lacquer can be dissolved even after it dries, and the oil had all night to work. You're seeing bare wood because it wasn't stained. Instead, the table was finished with a toner—a tinted film finish popular among furnituremakers. Toners make repairs harder because spraying toner on the entire surface darkens existing coats as it covers the bare spots.
If the table's finish comes close to matching a commercial stain, use that to touch up the damage, and seal the stain with varnish thinned 75% with mineral spirits. If not, make a touch-up toner by mixing pigments, such as Mixol (Woodcraft, (800) 225-1153), in 1⁄2 -pound-cut shellac, as shown above, or in thinned varnish. To avoid future problems, cover your repairs and the entire tabletop with at least two coats of polyurethane or alkyd-resin varnish.