Woodworker's Journal 2011-35-Winter, страница 40
Shellac: Simple And Sweet the "miracle" finish that comes from humble origins. A - suspect that if shellac were introduced today as a newly invented modern finish, it would be hailed as a near miracle. It boasts a wealth of characteristics that woodworkers routinely seek in a finish. Shellac is nontoxic, self-sealing, user-friendly, easily repairable, very fast drying, and can be applied by rag, brush, spray gun or even dipping. It brings ^ out the beauty of wood, and the primary solvent for it is grain alcohol — virtually the same stuff we quaff in beer, wine and liquor. But that's not all; it is such an effective barrier coat for almost all the contaminants that wood is prey to that some folks call it a "universal sealer." wood Super blonde A Bit of History In fact, shellac is anything but new. Its recorded use goes back some 3,000 years, and the water-soluble dye that comes out of the first washing of raw shellac was long prized for the bright scarlet color it gave to silk, leather and wool. We no longer harvest shellac for its dye because we have synthetic ones. Over the years it has been used not only as a coating for fine furniture and other objects, but also as an adhesive in musical instrument repair, an insulator and for a range of solid objects from jewelry to the precursor of our CDs — Edison's early records and cylinders. In fact, the invention of Bakelite (phenolic resin plastic) came about as an attempt to make "synthetic shellac." These days the bulk of shellac in the U.S. is used for coating medicine to make pills easier to swallow and as "confectioner's glaze" to make fruit and chocolate shiny. One of its more curious uses is in "time release" medicine. Shellac is highly resistant to acids but will break down Blonde Bug Doots: Tiny laccifer lacca swarm on trees in their larval stage, creating a protective crust. The encrusted branches are then harvested, the earliest stage of shellac. in basic (alkaline) solutions. Our mouth and stomach are acidic environments, but our intestines are basic. If part of a medicine is coated with shellac and part uncoated, the uncoated portion will go to work almost immediately in your stomach, while the coated batch won't start working until it makes its way down to your intestines. Clever, eh? Is it Really Bug Doots? Shellac is produced by laccifer lacca, a tiny bug that swarms on certain trees in India and Thailand. This parasite infests the trees in its larval stage and makes itself a protective crust during its development. At the end of the bug's life cycle, the ftilly encrusted branches are harvested and "seedlac," the crudest form of shellac, is scraped off and crushed. Washing the seedlac removes the water-soluble Orange Garnet 40 shellac: simple and sweet |
