Shellac is a common wood sealant. It is relatively environmentally friendly, mixes well with several colors and repair is simple if something happens to the wood. One of the major drawbacks to shellac, however, is it can cause brushes to stiffen to the point of nonusability. Follow a multi-step process to properly clean a shellac brush; it eliminates the shellac and keeps the brushes soft for further use.
What is Shellac?
Shellac is a naturally produced resin created by a red insect, laccifer lacca, that feeds on special trees in India and Thailand. The insects deposit the resin on the trees, and workers harvest it and take it to a mill for processing. There the resin is refined by removing insect larvae, parts and other particulates, and is turned into commercial shellac.
Pour a solution made of 50 percent water and 50 percent ammonia into a glass container. Place the brush into the mixture and work it into the brush for several minutes. The mixture emulsifies the shellac and allows it to be cleaned out with just soap and water. You may need to repeat the process several times to make sure the shellac is completely dissolved and out of the brush.
Place the brush into a container filled with denatured alcohol for several minutes. The alcohol dilutes and softens the shellac, making it easy to remove with soap and water. This takes longer than the ammonia method and needs several attempts to get the shellac completely out of the brush. Denatured alcohol is also not environmentally friendly and should not be poured down the drain or into the ground.
Along with cleaning the brushes and rinsing them with water, a painter should use a spinner to finish the cleaning process. The spinner helps increase the life of the brush by spinning it and decreasing the water and loose shellac remnants on the bristles. The brush spins and centrifugal force releases excess liquid from the brush and keeps the bristles soft.