Interior walls don’t usually need to be stripped before repainting; many homeowners can simply use a fresh layer of paint on the old. But when a wall has many layers of paint on it, or any time the previous inside latex is stained or chipped, removing the old paint makes it easier to use the next coat. Furniture painted with interior latex may also need to be stripped before refinishing. Traditional techniques of paint removal call for a lot of difficult work. Newer techniques can eliminate paint more quickly, but may be dangerous if used carelessly.
Mechanical removal methods utilize sandpaper, scrapers, wash brushes and other abrasive tools to physically scrape the paint off the surface it’s bonded to. For smaller jobs, a rotary tool with a nylon brush accessory or an oscillating tool with wood sand paper attachments work well. These techniques are inexpensive and require no more harmful chemicals. But, mechanical elimination is labor-intensive. Too-vigorous scraping also can damage drywall or plaster walls. Avoid using mechanical methods in elderly homes that might nevertheless have layers of lead paint. Airborne lead dust poses a significant health risk. Always wear eye protection and a dust mask when scraping paint, because even non-lead paint dust may lead to eye and lung irritation.
Heat stripping uses high temperatures to melt or soften paint, which makes it much easier to scrape the surface. Use hot air guns or tools using an electrical element, never a propane torch or other open flame heat tool. Open flames make a fire hazard and may scorch the wall. Even non-flame heat tools may cause some scorching if used improperly. Maintain the heat tool moving for best results. Most heat tools pose a burn hazard, and should be handled with care to prevent injury. Never use tools that produce extremely large heat; based on”Old House Journal,” temperatures above 1,100 degrees Fahrenheit may vaporize old lead paint, creating a health hazard.
Caustic paint strippers utilize sodium hydroxide or some other very acidic material to loosen paint. These chemicals break down the bonds in the paint, which makes it much easier to scrape the surface. These strippers may also cause chemical burns and damage eyes when used incorrectly or in areas with inadequate ventilation. If left in place too long, they can eat into the substrate below the paint, damaging walls and furniture. Neutralize the surface with a mild acid wash after having caustic strippers, to prevent softening and other damage. Never use caustic paint strippers on aluminum or on hardwood that will not be painted afterwards.
Solvent strippers have been in use because the mid-1950s. These paint strippers operate quickly, are user friendly and are reliable on a range of paints. They are also able to produce dangerous fumes that cause headaches, dizziness and poor coordination. Some, like methylene chloride, can be carcinogens. Use these strippers sparingly and in a well-ventilated space only. Solvent strippers are thought to be flammable, and must never be used around heat or an open flame.