How to Remove Finishes From Wood
Wood furniture and flooring usually have varnish, shellac, lacquer, or other clear coats applied to protect them from scuffs, stains, and scratches. Eventually, most people choose to remove these finishes from the wood grain so they can refinish, restore, or repair it.
Removing finishes from wood can be a lengthy and messy process, but it's a great way to give wood new life! A lot of people choose to do this when restoring furniture or fixing up their floors.
There are three main ways to remove finishes from wood depending on what type of finish you're working with including sanding, solvents, and strippers.
Sanding is a very labor intensive process, but can remove almost every kind of wood finish including paint, acrylic, lacquer, shellac, and varnish. Sanding is also good for refinishing wood, giving it a smooth surface.
There are a number of different sanders available. In most cases, a small power tool such as a handheld orbit sander can be used. For smaller or irregular areas, you should use either a handheld paper or a sanding block to make it easier to maneuver around. Use a 150-grit paper to first rough it up and then finish with a 220-grit paper. If you intend to paint the wood after removing the finish from it, sanding may be the only thing you need to do.
A high quality piece, particularly furniture that was made after 1930, is likely to have been manufactured using shellac or a lacquer finish. Alcohol-based finishes like shellac and lacquer can be removed using a number of different solvents that are easily found in any hardware store. Denatured alcohol can be used to remove shellac, but if that doesn't work try using a lacquer thinner.
To remove a finish using solvent, put the solvent on a rag and apply it to the finish on the wood surface. You can then easily scrape the residual finish with a plastic putty knife or scraper.
Chemical strippers can be a messy job, so be sure to protect the area you're working in. If you can, working outdoors might be best. Also make sure to use goggles and chemical-resistant gloves. Many chemical strippers contain the active ingredient methylene chloride, which is a harsh, caustic chemical that's dangerous to your eyes, respiratory system, and skin. Use proper safety equipment and be sure to do this in a well ventilated space. If you suffer from allergies or want something that's more environmentally friendly, look for water-based products such as 3M, also known as Safest Stripper.
To use a chemical stripper, start by putting it into a container such as an empty paint can and apply using a brush. Slather on a thick, wet coat, spreading it quickly and evenly. If the area is very large, you can pour the stripper directly onto the surface and use a brush to spread it around.
Different finishes react differently to strippers. Some will soften, others dissolve, and some even wrinkle. Either way, you'll be able to tell when it's working. After about 10 minutes you should be able to see if it's ready to be removed. Try a little test spot to see if it comes off easily. If it doesn't, apply more and let it sit for another 10 minutes or so. You can then remove the finish using a plastic or metal scraper for flat areas, or a stiff bristle brush around corners and inside grooves. It shouldn't take much effort to remove it. Once it is, you should use lacquer thinner to remove any residue.
The removed finish should be mixed in with either wood shavings or kitty litter in the old paint can you used. Leave this can outside without the lid until the solvents have completely evaporated. Be sure to dispose of it properly according to your city’s guidelines.