Fast strippers work great; they cut through finishes in minutes. But the fumes can make you dizzy and even do permanent damage to your brain or lungs. So my rule is to use them outdoors only. To recognize these strippers, check the fine print. Most contain methylene chloride and possibly toluene, acetone or methanol.
Most of the slow strippers contain “NMP,” a much safer chemical. NMP isn’t harmless; some studies suggest that long-term exposure can cause health problems. But for the occasional user, the main risks are irritation to your skin or respiratory system.
Pros and DIYers alike have told me NMP paint strippers “just don’t work.” That’s not true. NMP just requires more patience. Here’s my approach: Brush on a heavy coat of stripper and cover it with thin painter’s plastic or plastic kitchen wrap. Then I check back in a couple of hours. If the finish is easy to scrape off, I get to work. If not, I give it a couple more hours. I’ve waited up to eight hours and NMP has never failed to soften the finish.
Most home centers carry strippers that contain NMP (about $20 for a half gallon). You won’t find “NMP” on the label, so check the fine print for terms like “n-methyl pyrrolidone” or “1-methyl-2-pyrrolidone.” Citristrip and Zinsser Magic Strip are two common brands.