Finishing Brush Tips
When you apply a clear finish, your brush makes a difference. A cheap, throwaway model can cause problems, while a quality brush that suits your particular finish will help you achieve first-class results. You'll spend more up front, but that's not a decisive factor; take care of it properly, and a good brush will last much longer than a cheap one.
The photo above provides a cutaway view of a finishing brush made by the Elder & Jenks company, brushmakers since 1793. The bristles are set into a slightly convex base of epoxy, and then trimmed to complete the chisel shape. Double dividers give the bristles extra support. They also create reservoirs that hold a small amount of finish, feeding the brush as you use it.
When you apply varnish or brushing lacquer, opt for a "China bristle" brush made with hog hairs from China. These bristles, as shown in the drawing below, have a natural taper that provides strength while putting more bristles in contact with the surface. Their "flagged" ends hold more finish than pointed ones, and dispense it more evenly.
For water-based finishes, use synthetic bristles. Nylon bristles are softer and more flexible than polyester, or you can buy a combination of the two. Golden nylon gives great results with shellac. Some synthetic bristles also are tapered and flagged.
Once you have a top-notch brush, keep it in working order. It takes only a couple of minutes to clean and store it properly.
When you're done applying a coat of finish, brush out as much finish as possible onto paper or a piece of scrap. Put on protective gloves, soak the bristles in the appropriate solvent, and work it in with your fingers. If you used the brush with varnish, clean it with mineral spirits, then lacquer thinner. If you applied lacquer, clean with lacquer thinner. A shellac brush benefits from a bath in ammonia and hot water. Use water to clean out water-based finishes. When the bristles feel clean, shake the brush to remove most of the solvent, or hold the handle between your palms and rub your hands to spin it.
Finally, no matter which solvent you started with, finish cleaning the brush with soap (shampoo works well) and water, as shown in Photo A. Rinse out the soap, and then spin the brush to remove the water. Before it dries completely, place the brush in its original cardboard jacket, or wrap it with paper from a grocery bag, as in Photo B, to keep the bristles straight and clean. The next time you need it, your brush will be as good as new.
Photographs: Marty Baldwin Illustration: Roxanne LeMoine