Heat strippers such as this paint strip gun from Ryobi have several advantages over chemicals.
To uncover good-looking wood beneath layers of old paint — detailed trim, a carved mantle — there are two choices: chemicals or heat. Both soften paint so you can scrape it away, and both are faster and easier than sanding. But speed has a price, mainly dealing with noxious fumes and caustic solvents.
These guidelines will get you through the process safely, starting with an obvious option. If it's portable, like a chair, you could send it out to a shop where pros use spray booths and vats of stripping agents. At home, a second choice for furniture is to spread a tarp and work on the project outside. If you must work inside, create a ventilation path away from the work area to an open window.
Testing for lead If the wood might have been painted before 1978 when lead paint was banned, test its content with an inexpensive swab-type kit. Stripping doesn't release harmful lead dust, but touch-up sanding will.
Checking label cautions Many stripping products call for special handling. Typically, personal protection includes at least rubber gloves and safety glasses. You may also need a dust mask or respirator. In some areas (call local authorities to check), there may also be restrictions on disposal of old paint and caustic chemicals.
Removal tools Putty knives work best on flat surfaces, with heat or chemicals, plus a lot of paper towels. For difficult nooks and crannies, try a sharpened triangular scraper, a knife and, on intricate leg turnings, a ball of twine that picks up the residue as you move from one crevice to the next.
Chemical strippers There are solvent- and water-based strippers, available as liquids and pastes. Liquids generally work faster, but pastes cling to crevices and vertical surfaces where liquids run off. Solvent-based strippers are applied with a natural bristle brush and cleaned up with paint thinner.
The standard ingredient is methylene chloride. OSHA describes it as a "potential occupational carcinogen," although that's for people with daily exposure in the workplace. But you may want to check the Material Safety Data Sheet (MSDS) for the product you use. Most manufacturers post them on the Web. Solvent-based strippers can save time because they don't raise wood grain and require only light sanding to finish. Water-based strippers clean up more easily but often leave a slightly furry surface that requires considerable sanding.
On walnut, oak and mahogany you may need to scour the surface once the paint is removed to clear residue from the open wood pores. Otherwise the wood can appear speckled, specially if it was painted with a light color. Clear at least most of the little dots by saturating a pad of medium-gauge steel wool with remover and rubbing with the grain.
Heat strippers I've tried chemicals and heat many times, and heat wins. The up side is no caustic solvents, no waiting 15 or 30 minutes for the chemical reaction to soften the paint, no second and third applications on multilayer paint, minimal finish sanding, and easier cleanup. The caveat: Use a heat gun, not a torch with a flame.
Both soften paint, but a flame too close to the surface can ignite paint and char the wood underneath. That means even more refinishing. Modern heat guns (like hair dryers except hotter and more concentrated) offer variable temperature settings. But you can also control the heat by moving the nozzle closer or farther away from the paint, working one area at a time.
Keep the gun moving a few inches from the surface until the paint begins to blister. Remove the heat if paint begins to smoke. Then use a putty knife at an angle to scrape it away.