DIY Network

Stripping Old Finishes From "Refinishing" episode DIF-101

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Figure A Figure B Figure C Figure D Figure E Figure F Figure G Figure H Figure I Figure J Figure K Figure L Figure M Figure N Figure 0 Figure P

Preparation and Safety Precautions

Furniture-restoration expert Bruce Johnson, host of DIY Refinishing, introduces the proper techniques and materials needed to safely remove old finishes from wooden furniture and antiques.

Over time, the original clear finish on an antique can become worn, damaged or discolored (figure A). Paint finishes may crack, chip or peel. Restoration usually requires removing the damaged finish--stripping the piece down to the bare wood.

Since stripping is messy, it's best to work outdoors. A garage or basement, with proper ventilation, is an alternate choice. Work a safe distance from walls, furniture, etc., to prevent damage from spills. Spread a heavy drop cloth to protect the floor, then cover the drop cloth with several layers of newspaper to absorb chemicals and dissolved finish. If you're working indoors, open all doors and windows, and if possible, use a fan to improve ventilation (figure B), as stripping chemicals give off fumes.

Wear heavy-duty rubber gloves--not thinner surgical-type gloves--to protect your skin from the harsh chemicals. Safety glasses protect your eyes from splashes. A respirator may be worn to reduce inhalation of chemical fumes, which may irritate the lungs. Don't confuse a respirator, which actually captures fumes, with a particle mask (figure C), which merely filters out dust and other particles.

Sanding and scraping aren't recommended for removing old paint or finish. Hand-sanding is slow and tedious, and belt-sanders clog quickly with old paint and may damage the wood. Avoid using old-fashioned metal scrapers or chisels, as they'll cause gouges and scratches. The best way to remove an old finish is to use a paint-and-varnish remover, or chemical stripper.

Chemical Strippers

Chemical strippers--the preferred method of removing the finish from wood--fall into three categories, each with its own distinct properties and application techniques. All strippers contain caustic chemicals, so follow the manufacturer's recommendations to the letter, and wear heavy-duty rubber gloves and a respirator when using them. Work outside or in a well-ventilated room.

The most commonly used chemical strippers are those containing methylene chloride. These are available as a thick semipaste, designed to cling to vertical surfaces, and in liquid form (figure D), which is useful when stripping a piece with carvings or ornamentation. Both contain a wax component that slows evaporation, allowing the chemicals to remain on the wood longer.

Shake the can thoroughly to mix the contents before opening, then pour stripper into a shallow pan. Work on one small section of the piece at a time rather than attempt to strip the entire piece in one step.

To strip old paint, apply a thick coat of remover uniformly over the surface of a section with an inexpensive paintbrush. Leave the coating undisturbed for about 20 minutes, until the paint begins to bubble up. Remove the softened paint with a plastic scraper (figure E). If necessary, apply a second coat of stripper.

After another 20 minutes, use a pad of coarse steel wool dipped in mineral spirits or lacquer thinner to scrub off the last bits of remaining paint (figure F). Finish by wiping off the section with a soft cloth dipped in clean mineral spirits.

Note: The final step of rinsing the surface with mineral spirits or lacquer thinner is critical to avoid problems when sanding and staining. Avoid strippers advertised as "water-rinse" or "no rinse."

Methylene-chloride strippers are not the only option for removing old varnishes. Furniture refinishers--wax-free solutions containing a blend of solvents such as lacquer thinner, denatured alcohol and mineral spirits--are a good choice for removing varnishes such as shellac and lacquer. To determine whether a particular finish can be dissolved with furniture refinisher, perform this test: Moisten a cotton ball with a small amount of solvent-based fingernail-polish remover, and rub it on a small area of the finish. If the cotton ball turns brown, the finish is dissolving--indicating that it can be removed with a furniture refinisher.

Furniture refinishers contain no wax and evaporate quickly, so it's best to work on small sections at a time.

Pour furniture refinisher into a shallow pan, and dip in a soft cloth. Rub the moistened cloth over the old finish until it begins to dissolve (figure G). Rinse the cloth in the refinisher and continue rubbing. If the finish is particularly difficult to remove, switch to a pad of fine or medium steel wool dipped in refinisher. Finally, wipe down the surface with a soft cloth dipped in clean refinisher.

A third category of removers, known as "safe strippers," may be useful for those who are sensitive to harsh chemicals. Safe strippers contain fewer caustic ingredients, but they're generally more expensive and take longer to soften the finish. The techniques for using safe strippers are similar to those described above:

Shake the container of remover thoroughly. Brush a heavy coat of safe stripper onto a section of the piece, taking care not to over-brush (figure H). Lay a piece of waxed paper over the remover to slow down evaporation (figure I). Once the finish has softened, use a plastic scraper to remove it. Apply a second coat and cover with waxed paper. After a few minutes, scrub off the remaining softened finish with a pad of fine steel wool. Wipe the piece clean with a soft cloth.

Special Stripping Jobs

To strip wicker and metal, you'll need techniques somewhat different from those used to strip wood.

It's sometimes possible to strip old paint or varnish from wicker, though not always as successfully or as easily as with wood. Begin by brushing on a thick coat of paint-and-varnish remover, working it deeply between the strands (figure J) . To keep the surface wet, spray on paint-and-varnish remover from an aerosol can. When the finish softens, use a small, stiff brush to remove it (figure K) . Brass or natural bristles are suitable, but avoid using wire brushes, which can damage the wicker strands.

Cut the bristles from a paintbrush, leaving about 1/2" of stiff bristles (figure L), and use it to scrub off remaining loosened paint with mineral spirits.

Wicker is less likely than wood to be damaged by water. In fact, if the wicker is unfinished, an occasional misting is sometimes recommended to keep the material flexible. When stripping wicker outdoors, you can use a forceful stream of water from a garden hose to blast away loosened paint.

Old layers of paint that have built up over the years can be removed from metal patio furniture using methods similar to those employed with wicker.

Brush on a thick coat of paint-and-varnish remover, and allow it to stand for about 20 minutes. Use a coarse rag or bristle brush to remove loosened paint (figure M). Avoid steel wool, which may scratch softer metals. If necessary, apply a second coat of remover. Use a bristle brush or synthetic pad to remove the last of the softened paint, then wipe the piece with a rag dipped in mineral spirits (figure N).

Once you've stripped the piece to bare metal, avoid letting it come in contact with water, which can cause rust to form almost immediately. If rust spots appear, sand them off before repainting.

Last-Minute Tips and Cleanup

Once you've stripped a piece, you may notice a few places you've missed--such as in carvings or around detail work. It's best to remove these remnants of finish while it's still soft from the stripper. Use an old toothbrush or cotton swabs dipped in mineral spirits to remove finish in difficult areas (figure O). Follow up by wiping with a soft cloth. Leaving small amounts of the old finish deep in the crevices and carvings can help preserve an antique look.

Unused portions of stripper may be saved for future projects as long as the container is tightly sealed. Waste stripper, paint sludge, old brushes and used steel wool may be placed in a sealed container, then disposed of. Call your local sanitation department to find out how and where to dispose of the waste: community regulations on the disposal of toxic materials vary widely.

As you clean up, note that chemical-soaked rags can spontaneously combust and cause a fire. To dispose of them safely, place them in a container, fill it with water (figure P) and seal it. Dispose of the sealed container with household garbage. Leave soiled drop-cloths and newspapers outside to dry, making sure to keep them away from pets or children, before throwing them away. Or soak drop-cloths and newspapers with water and throw them away.