DEAR TIM: I have to strip some paint and clear finishes from an older home. Some of the paint to be removed is latex while the remaining is older oil based paint. There are places that have perhaps 20 coats of paint or more. Do I need to use different strippers? What is the best way to apply and remove paint strippers? Do you have any tips on making this job go as smoothly as possible? Mark - Kansas City, MO
DEAR MARK: Make sure you take your reading glasses with you to the home center. You are going to need them. There are numerous paint stripping products. Some work better on latex paints while others work better on oil based paints. To further complicate matters, some paint removal products can harm fine furniture that you intend to re-stain and clear coat. You must take your time and do diligent research to obtain the best results.
Paint strippers contain different types of active ingredients. Aggressive solvents such as methylene chloride can be found in certain strippers. Other strippers contain caustic ingredients like sodium hydroxide. There are other new "safe" strippers that contain other chemicals. These chemicals soak into the paint and soften the film. With many strippers, the softened paint finish begins to swell. This swelling produces tension forces that cause the paint layers to delaminate from one another and the wood or metal you are refinishing.
Strippers that contain methylene chloride can often remove 4 to 5 layers of old oil based paint at one time. However, some of these strippers seem to be able to remove only a single layer of latex paint per application. Certain new "safe" strippers do just the opposite. They seem to work better on latex paint films than oil paint.
You can buy a stripper that contains sodium hydroxide that claims it can remove up to 30 layers of paint in one application. This stripper has a very thick paste-like consistency much like drywall joint compound. It is troweled onto the surface and covered with a special paper. The paper inhibits evaporation of the stripper. This allows the stripper to penetrate deeply into multiple layers of paint. Once the stripper has softened the paint, you remove the paper and old paint in one simple step.
Paint strippers work the best when applied and removed in temperatures that range between 60 - 85 degrees F. It is best to work in a shaded area that has good ventilation. Direct sunlight, windy conditions and excessively high temperatures can cause many strippers to dry too quickly. Covering paint strippers with plastic film or aluminum foil will help them stay moist for a longer period of time.
To obtain the highest performance from a paint stripper it must dwell for an extended time on the paint. This means let the stripper do the work, not you. All too often people apply a stripper and expect results within minutes. Some strippers take hours to soften multiple layers. The top layer of paint will bubble and blister very quickly in most instances. However, the stripper may still be working. Often the liquid portion of the stripper is driving deeper into the layers of paint. If you scrape off the paint film too early you may remove active stripper that has yet to do its job! It is best to read the directions on the can and follow them to the letter.
Clear urethane finishes can be tough to remove. To make sure that you increase your chances of success, sand these surfaces with rough sandpaper before applying the stripper. This allows the stripper to penetrate more rapidly into the tough urethanes. Be sure to read the label before you buy the stripper. Some strippers will not work well on certain clear finishes.
Author's Note: We've received other questions about similar problems. Here's one from Leigh, in Columbus, OH.
"I have a cement pad/stoop located in front of my front door. The previous owners painted this a dark brown. The paint is chipping off. I was wondering if you could please tell me how to remove this paint? The pad is in good condition, and I would much rather prefer a 'natural' cement color! Thank you! "