DO-IT-YOURSELF : Reaching for the Bleach

When discolored areas won’t sand off or you wish to lighten the wood’s color, reach for the bleach.

Stripping a piece of furniture will lighten it, but bleaching for cosmetic purposes will make the wood look fresher still. This simple technique can transform a chair, picture frame or entire room of wall paneling.

When dissimilar colored woods have been used in a piece of furniture, the darker parts can be bleached to produce a uniform tone.

Simple laundry bleach, used full strength, may be enough to remove water marks, ink stains or other blemishes, or to lighten oak ash, mahogany, maple, walnut and beech. Other species--chestnut, poplar, cedar, rosewood and cherry, for example--resist bleaching.

If laundry bleach doesn’t do the job, try a commercial two-step wood bleach. Such wood bleaching kits, sold at hardware stores and home centers, contain sodium hydroxide (lye) and hydrogen peroxide mixed together. Used improperly, these compounds can ruin good furniture. Always test the bleach in an inconspicuous spot.

(Caution: Two-step bleaches are very caustic. Follow the directions on the label carefully. With any type of bleach, wear rubber gloves and safety goggles, and work in a well-ventilated area.)

The key to getting a good bleaching job is removing all the old finish before you start. A thorough stripping job is vital; even the slightest patch of old finish will prevent bleach from penetrating, leaving a dark stain. To test the wood after you have stripped it, wet it. If it darkens evenly, it will bleach to a uniform color. Any areas that remain light must be stripped again.

Here are some helpful tips:

* Protect the work area with newspapers covered with plastic garbage bags.

* Remove all metal hardware; the metal may be attacked by the bleach.

* Use an old brush or a clean cloth pad to apply an even coat of household bleach to the wood. (The two-step kits recommend using a plastic sponge or a paintbrush with nylon bristles.) Wipe evenly along the grain over the entire surface. Avoid overlapping onto the sections that have already been bleached.

* Leave the surface wet for 30 minutes, then neutralize it with a 50-50 solution of white vinegar and water. Rinse with warm water.

* Let the wood dry for three hours before you decide whether it needs another application. Use spot applications to touch up areas where the color is uneven. Neutralize and rinse after each application.

* Allow the wood to fade to a shade slightly darker than the desired color; it will appear lighter after it dries.

* Don’t overdo it. After four or five applications, the wood may start to look gray and lifeless. If that happens, improve its appearance by wiping on a light stain to highlight the grain.

* Let the wood dry overnight or as long as the label directions recommend.

* Because the bleach will have raised the grain of the wood slightly, sand twice; first with a medium sandpaper, then with a finer grit. But sand carefully; if done too vigorously, you can sand through to the original color.

* After bleaching, protect the wood with a wipe-on oil finish.