A favorite of French polishers and crafters alike, shellac is a fantastic go-to sealer for do-it-yourselfers who want an easy-to-use product for sealing and finishing wood. Shellac was once the normal sealer for architectural woodwork and inside doors. Whether you’ve got a grand Victorian manse or a modest, 1930s row home, you will discover shellac creates a warm, lustrous surface your neighbors will envy.
Shellac is a leaf secreted by the lac bug, a scale insect from the East Indies. The leaf is processed to shellac flakes, which can be dissolved in denatured alcohol for use. Some old-timers still purchase dry shellac flakes and mix them with denatured alcohol themselves. Prepared shellac has a one- to three-year shelf life. If the shellac isn’t fresh, test it by smearing some on a piece of scrap wood. If the shellac doesn’t harden by the morning after, don’t use it.
Prepare surfaces by cleaning them with a household cleaner and rinsing thoroughly. Use 220-grit sandpaper to smooth out rough spots and give the surface a scratchy finish. Wipe away dust with a damp cloth. If it is functional, remove doors and then place them on sawhorses or another horizontal surface for better control during program. Cover floors and neighboring objects using a drop cloth or a plastic tarp. Ventilate the room; use a fan if necessary.
Soak a broad, natural-bristle brush or a clean, lint-free cloth in the shellac and wipe away excess on the side of the container. Working with the grain, apply shellac with long strokes, working fast and always next to some “wet edge” to prevent marring a partly dried surface. If the shellac becomes sticky during program, thin it with denatured alcohol in a 1 to 1 ratio for the initial coat. The surface is prepared for a second coat once it dries hard in about one to four hours.
Use 320-grit seams between coats to smooth brush marks and then knock stray pieces of debris and dust. Employ multiple coats until you attain the richness and color you desire. Do not sand the last coat. To prevent conspicuous brush marks that go against wood grain, work first on members whose grain dissolves in other members. On a two-paneled door, for example, finish the panels first, then the horizontal top, middle and bottom rails, and ultimately the vertical stiles.
Should you need to stain your woodwork or doors, cut shellac to one third strength with denatured alcohol and use it like a staining sealer to prevent blotchy staining. When dealing with paint, white-tinted shellac, marketed as alcohol-based primer, prevents knots, resin deposits and waxy or oily spots from showing through the top coat. Use it to reduce rust on steel tools or to get quick touch-ups on woodwork and hardwood floors.