This month’s Modern Woodworking, in cooperation with the Woodweb, presents a new series of how-to articles on sanding and finishing — problems and solutions to common woodworking situations encountered in the day-to-day work process. The solutions come from you, the hands-on experienced workers who deal with these specific problems and have found particular ways of solving them. For more information, or to add your own solutions, please contact us through the web at www.modernwoodworking.com, or www.woodweb.com.
Problem:
A store fixture customer wants to switch from laminates back to white oak (in products that are exposed to direct sunlight). A designer has advised that the new finishes present no yellowing problem. The contractor is skeptical and wants to know: “Do the new UV resistant finishes really resist yellowing that well?”
Response A advises: “Guardsman/Lilly adds a a UV block to its coatings. I have seen no color change at all. There are certain waterborne coatings that do not yellow, but that does not mean that their applications stop the substrate from exhibiting a color change.”
Response B advises: “Look for an acrylic finish. Any finish that has nitrocellulose in its make-up will yellow. When you use a finish that has a UV absorber, you are only slowing down the yellowing. At some time that UV block will get used up and the product will start to yellow. Your acrylic finishes hold their clear color better than any other coatings.”
Response C advises: “I have used Sherwin Williams acrylic lacquer with its vinyl sealer for seven years with never a yellowing problem. It is especially good for paint-grade white, which is very difficult to get non-yellowing. I use a white vinyl sealer tinted for color and then its acrylic topcoats”
Send your questions and/or solutions to common manufacturing problems to Modern Woodworking, Randall Publishing, 3200 Rice Mine Road NE, Tuscaloosa, AL, 35406, and we’ll try to find answers to difficult sanding and finishing problems for you.
