Wood Finish Repair: How to Remove Shellac
Repairing a worn wood surface is a great way to breathe new life into an old piece. Unfortunately, removing the old finish isn’t always easy. For older wood surfaces, the finish is likely either shellac or lacquer. Whether you are repairing a piece to sell or to enjoy for years to come, here are a few ways to remove shellac finishes.
Determine the Finish
The first step in repairing an old wood surface is to find out the type of finish originally applied. You can accomplish this by using some denatured alcohol and an old rag. If the wood was finished before the ‘20s, there is a strong chance it could be either shellac or lacquer. Fortunately, denatured alcohol dissolves shellac, but not lacquer. Simply dab the surface with some denatured alcohol and if it gets sticky, then you’re dealing with shellac. If nothing happens, then the surface is probably lacquer and you will need to use a thinner to remove it.
Removing Shellac With Solvents
You can remove shellac with a variety of solvents, including denatured alcohol. While this method is messy to clean up, it is the least labor intensive. Simply moisten a rag with denatured alcohol and rub it into the surface in a circular motion. The alcohol will eventually soften the finish until it becomes sticky. Once it starts to separate from the wood you can began to wipe the finish away with another rag. If you have trouble removing the shellac, use a dull scraper, especially in corners or hard-to-reach places. You should progress in small sections and give the alcohol plenty of time to work its magic.
You can remove shellac (and most finishes, for that matter) via sanding. You can do the sanding by hand or with a power tool—just make sure all the old finish is completely removed before applying the new finish. Start with a lower grit sand paper, such as 150 grit, and work your way up to 220 grit. Remove any dust particles with a tack cloth and make sure to work in a well ventilated area. After the sanding is complete, clean the surface of the wood with a damp cloth and allow the area to dry before moving on.
Removing Shellac With Chemicals
Removing shellac with a chemical stripper is an effective method that will not damage the wood. The downside to chemical strippers are their health hazards. These types of chemicals can damage your lungs, eyes, and skin, and are not healthy for the environment. With that in mind, chemical strippers should be used as a last resort and be handled with extreme care. Make sure you are in a well ventilated area and wearing appropriate safety gear. You may even need to use a fine steel wool to help remove the finish. Scrub in the direction of the grain and wipe away with a clean cloth.
It doesn’t take much to damage the wood surface, especially if the wood is antique. Taking a few extra precautions when removing the shellac will prevent any unwanted damage. Always begin the removal process with the least abrasive method (denatured alcohol) and only move to another option if it doesn’t work. Using an ultra-fine steel wool is preferable to sandpaper, which should only be used for the most stubborn of places. Finally, be extra patient throughout the removal process and give your materials enough time to work before moving forward.
There are a number of safety concerns when removing shellac from a wood surface. Denatured alcohol is very flammable and can be harsh on the skin. It also releases a bountiful amount of noxious chemicals into the air. If possible, strip the old finish outdoors. If you have to work inside, open as many windows as you can and turn on a few fans to circulate the air. Always wear rubber gloves when removing finish and dispose the dirty rags in an airtight container.