How do I repair a spill-damaged finish?

Mix pigments and shellac on a piece of scrap glass to determine the right color before dabbing it on.

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 percent with mineral spirits. If not, make a touch-up toner by mixing pigments, such as Mixol (Woodcraft, 800-225-1153 or woodcraft.com), in ½-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.

Read more about

Tip of the Day

Easy-change chuck-in-a-chuck

My drill press has become much easier to use thanks to a keyless chuck I salvaged from a dead... read more