Woodworker's Journal 2004-28-6, страница 60
ake a mistake type of finish do you recommend for salad bowls and cutting boards? I have heard ■r using walnut oil, but some people are allergic to nuts. 1 have also heard of using mineral oil. What are the 4 llllslit i;.; Jfj'.H pros and cons of various finishes that will be in contact with food? EK^.'' Marty Mandelbaum ^ Mt Sinai, New York 1 Before you commit to ^g^i^ Jf f ™ oil, consider leaving the wood raw. Unfinished wood has a long history of J food contact, from the ancient wood ffWLit ' ^ platters called "trenchers" that HHHBllmjuT ^ gave us the term "trencherman" j^Jbf | for a hearty eater, to the unfin-. ished spoons and spatulas in most kitchens today. 1 . Admittedly, both drying and non-drying oils » bring out the figure and color in wood, but there is a difference between the two. Drying oils cure to a solid film after being absorbed into the wood. Oils pressed from nuts are typically drying oils, and include walnut, linseed and tung oils, ^^HEf' among others. Most cure very slowly. Once BJHv fully cured, they form an inert plastic, and jflpa, imPar* flavor to food, nor will they wash off easily. Whether a person can IBM I 'iave an aHerg^c reaction to cured oil At depends on that person's degree of allergy. Vegetable and mineral oils are non-drying and t "Xa remain wet indefinitely. Thus, they impregnate ^^mL^m/i wood, but will wash off with detergents, and can impart flavors to foods. We usually avoid vegetable oils because they can become rancid. Mineral oil, derived from petroleum, is edible and has no discernable taste, making it an acceptable alternative for food contact items. Michael Dresdner For simply sending in his question on food safe oils, Marty Mandelbaum of Mt Sinai, New York wins the Olympic 5r»tci1or Wood Finishing Kit shoton at left. The small amount of almost-dry pigment clinging to the tips of my brush brings out the grain of this rather plain ash. As each tiny bristle catches on a grain line, it will deposit a small spot of color, enhancing the grain without changing the overall color significantly. To make it a bit easier, sand the wood, then flood it with hot water to raise the grain. Don't sand after the wood dries, but instead allow the slightly rough raised grain to pick up color from the dry brush. Oxidation Purpleheart is a tree with deep purple heart wood; however, it has a curious quirk. When you machine or sand it, the wood loses its deep color and instead turns a drab grayish purple. In the lead photo, you can see the color difference in the small section 1 sanded. Normally, we try to sand or machine as close to the time we apply finish as possible, since long exposure to air prior to coating causes adhesion problems; however, with purpleheart we make an exception. Exposure to oxygen in the air will restore the color of purpleheart in just a day or two, so wait until the color returns before you apply the finish. Don't expose it to sunlight, as that will cause the purple to fade. When it's time to finish, choose a clear coating, but not amber or your piece will turn amber over time. Any yellow tint will turn purpleheart brown. Both blonde shellac and waterbased coatings are good choices, as they are both clear and neither will yellow over time. Michael Dresdner's latest book, Wood Finishing Fixes: Quick Answers to Over 175 Most Frequently Asked Questions, is available from Taunton Press. 60 December 2004 Woodworker's Journal |
