Methylene chloride, the main solvent in many “fast” strippers, can cause skin and lung irritation, exacerbate the symptoms of heart disease, and may cause cancer. If you have heart disease, are pregnant or are elderly, avoid using strippers that contain methylene chloride. Inhaling methylene chloride reduces the amount of oxygen in the blood and can trigger a medical emergency in people with heart disease. With methylene chloride strippers, you can’t detect when an organic vapor respirator becomes ineffective, so rely on maximum ventilation when using them.
To minimize your risk, take the following precautions:
Work outdoors or in a well-ventilated indoor area and keep your exposure time short.
Wear long gloves, an apron, shoe covers and a face mask to keep methylene chloride off your skin and clothes. Wash your hands and face with soap immediately after using the stripper.
Since methylene chloride readily penetrates neoprene (rubber) gloves, wear only chemical-resistant gloves.
Choose a Stripper
Except for “refinishers,” which are only for shellac and lacquer, most strippers will remove just about any finish. Choose a stripper based on its speed and safety. A good rule of thumb: The safer it is, the slower it works. You can choose fast and hazardous, moderately fast and moderately hazardous, or slow and relatively safe. Be aware that the safety requirements for each stripper may differ; read labels carefully.
Some modern finishes won’t budge for any stripper, but they’re rare. Occasionally, very old pieces may be covered by a thin, milk-based paint that also is resistant to normal strippers. However, it will come off with a caustic stripper.
Slow and Safe
Safest Stripper, made by 3M, can be used indoors without special ventilation or gloves (although if your skin is sensitive, you may want to wear them anyway). Safest Stripper is particularly effective on oil-based paint and polyurethane. However, it can take as long as 24 hours to soften a finish. Safest Stripper seems to pull oil-based finish out of the pores better than other strippers, so it’s handy for woods like oak and ash. Because it’s water-based, it will raise the wood grain and can loosen veneer.
Fast but Hazardous Strippers
Refinishers work only on plain lacquer or shellac. Read the label. They contain powerful solvents like acetone and toluene. Refinishers dissolve the finish instantly but are highly flammable. They’re used differently than other strippers: Wearing gloves, goggles and respirator, soak steel wool or an abrasive pad with refinisher, scrub the surface and wipe off the finish as it liquefies. The finish will start melting almost immediately. Repeat until you are down to bare wood.
Methylene chloride (also called dichloromethane or DCM) strippers soften all finishes, including paint, in as little as 10 minutes. These strippers are identifiable by labels that say “extra heavy duty,” “tuffjob,” “super-strip” or the like, indicating that they contain a high percentage of methylene chloride. They work from the bottom up, so the finish comes off in sheets (Photo 1). Because they work by making the finish let go of the wood, you often need to use less of this stripper than other types. Work outdoors or in a very well ventilated area. As an added precaution, use a respirator with organic vapor cartridges.
Medium-Fast, Moderately Hazardous Strippers
Solvent mixtures may contain small amounts of methylene chloride mixed with other solvents, or new nonflammable stripping agents such as n-methyl-2-pyrrolidone (NMP) and gamma butyrolactone. You still must wear gloves and goggles, and most require ventilation. These strippers work from the top down (Photo 1). For many folks they represent a happy medium, since they are relatively safe yet relatively fast.
Caustic strippers are strong alkalines such as lye. Peel Away 1 is one example of this type of stripper. Although water-based and non-flammable, they can seriously burn your skin and eyes, so wear goggles and gloves and be careful not to splash. Because caustic strippers are water-based, they raise the wood grain and can loosen joints and veneer. They also may darken the wood, so they’re often used when the wood will be repainted. Unlike other strippers, they can’t be left on too long, or the wood itself may get damaged.
