An effective method for removing old paint from plaster walls is to scrape the paint from the plaster surface. If the paint is peeling, scraping does not require much preparation, but when the paint is intact, it must be pretreated with a chemical stripper before it can be scraped off.
- Prepare for scraping
Cover the floor at the base of the plaster wall with a drop cloth to catch the debris that results from scraping the plaster. Put on a pair of safety goggles and a face mask to avoid ingesting paint chips.
- Scrape off loose paint
Hold a scraping tool, such as an oscillating tool with a scraping blade, putty knife or plastic scraper, against the wall, with the edge of the tool placed along the edge of the peeling paint. Run the flat edge of the scraper across the wall, scraping the peeling paint from the plaster surface beneath. Continue scraping the wall, working the edge of the scraping tool beneath the upturned edges of patches of peeling paint.
- Strip the paint
Using a paintbrush, apply a chemical paint stripper to any remaining paint on the plaster walls. Cover a small area of the wall, about 4 square feet, with the stripper. Allow it to sit for five minutes so that it seeps through the paint, loosening it from the surface. Scrape away the loose paint with the scraper tool, then move on to an adjacent patch of paint, and repeat the process until all paint is removed.
- Neutralize the chemical paint stripper
Rinse the stripper from the wall using a sponge soaked in cool, clean water. Wring out the sponge, and soak it again before removing the stripper from each patch of removed paint to avoid spreading the stripper.