Of all the methods you can use to remove paint, heating it with a torch is the most extreme. The flame softens the paint, making it easier to scrape off, but it also heats the surface the paint is covering. If it's a flammable material, you run the risk of starting a fire. If the surface is wood, it may start smoldering from behind and catch fire only after you have finished working. For this reason, you should use a torch to remove paint only from nonflammable materials, like metal, and only if the paint does not contain lead.
Things You'll Need
Lacquer thinner or acetone
Light the torch and hold it 6 inches or more from one end of the surface of a pipe or metal plate. Move the flame along a section of the surface or around the pipe and keep it moving to prevent overheating the surface.
Remove the flame as soon as the paint begins to blister. Scrape the softened paint immediately with a paint scraper, before it has a chance to harden again.
Begin heating another section of the surface as soon as you have scraped the paint off the first section. Work your way along the surface to the other end in this way.
Return to the beginning after you have scraped off as much paint as you can with the scraper. Heat areas that still have paint on them until the paint softens, then work off the paint with a wire brush. If the paint gums up the bristles of the brush, remove it from the brush with the paint scraper.
Let the surface cool completely, then remove stubborn residue by soaking the bristles of the brush in a solvent like lacquer thinner or acetone and brushing it off. These solvents are flammable, so don't use them, or even keep them nearby, until the surface has cooled and you are finished with the torch.
Sand the surface with medium-grit sandpaper to remove any remaining residue and to prepare the surface for repainting.
If you use this method to remove paint from wooden furniture, do it outside near a garden hose so that if the wood catches fire, you can extinguish it quickly. Keep the flame away from flammable materials like insulation. If you are working in tight quarters, place a heat shield between the surface you are working on and anything that might catch fire.
Your local fire prevention authority may require a permit before using an open flame to burn paint off. Don't use a torch to burn off paint that you suspect contains lead. The flame will vaporize the lead, which is poisonous, and you may then breathe it in.