Popular Woodworking 2005-12 № 152, страница 21
Q & A continued from page 16 to the shop and put weight on them to try to get the cup out. Is the problem the humidity change? (The table will eventually be in an air-conditioned house.) What is the best way to fix it? What should I do to prevent it in the future ? If I put the top on the table frame and screw it down close to its edges (allowing for seasonal movement) that would probably take out the cup but would that solution be likely to fail? Is the problem due to moving the panels too early after milling and gluing? Bruce Meuth Mont Belvieu, Texas It's likely that your problem will correct itself. If the panel was flat in your shop then it likely will be flat when it reaches equilibrium inside your house. Chances are the problem is that there was a period when one face of your boards was shrinking faster than the other face, causing the cup. This sometimes happens when you have a board with one face on a bench and the other face exposed to sunlight, or some other heat source that reduces the moisture content more quickly on the exposed face. In all likelihood the top will return to flat when both faces of the boards reach the same moisture content. — Christopher Schwarz, editor How Do You Disassemble Chairs? I need to disassemble three maple Windsor side chairs - the dog has made many teeth marks in the chairs' stretchers. What type of glue does the chair industry use? (The chairs are of a 1965 vintage.) What technique - water, steam, alcohol, heat - should I use? I can drill some holes in the underside because the chairs will be painted in their new life. I have new side and medial stretchers in hand. Roger Kerr Stockbridge, Michigan Modern yellow glues (polyvinyl acetate) were invented after World War II. Before that, almost everything was built using hide glue. The first thing to do is to inspect the chair closely and determine if any of the joints have been reinforced with pegs or have had screws or nails driven into the joints. These must be drilled out or removed. If you're lucky, you should be able to then disassemble the stretchers and legs of the undercarriage with mallet taps. If the joints are stubborn, the next step is to try using a spreader clamp to gently apply pressure to dislodge the joints. If that doesn't work, you can drill a small hole in the joint and inject a solution of 50 percent warm water and 50 percent vinegar into the joint. Allow the solution to soak in and then try the mallet and clamp again. Scrape the joints clean, trying to remove as little wood as possible. You can tighten up ajoint by wrapping a wood shaving around the tenon and then gluing the tenon, shaving and mortise together. I prefer hide glue for chair repairs because it has a longer setup time and is reversible with heat and steam. However, yellow glue will work fine. Some people prefer to use epoxy as it has gap-filling properties, which can further tighten up a joint. PW — Christopher Schwarz, editor PI & mi'ffl' in i Iff^lM i j \ '■; v ill m: ' v M ■iMti' iMf if >11 iiifili ill l! ! i11" mfrfi 1 III INTRODUCING WOODWORKING SAW BLADES FROM DEWALT® You put a lot into your work. After all, it takes countless hours to complete the perfect project. And when you have the right tools and the right wood, you need the right saw blade. One that's precision balanced for highly accurate cuts. With large, micro-grain carbide teeth for exceptionally smooth finishes. Ultra-sharp cutting edges to reduce splintering. And one that comes in a variety of tooth counts and configurations. DeWALT® Woodworking Blades. We put more into them, so you can get more out of them. For more information, call l-aoo-4-PcWALT or visit our web site at mm ©2005 DeWALT. The following are trademarks for one or more DeWALT Power Tools and Accessories: The yellow and black color scheme; the "D"-shaped air intake grill; the array of pyramids on the handgrip; the kit box configuration; and the array of lozenge-shaped humps on the surface of the tool. popularwoodworking.com 19 CIRCLE NO. 175 ON FREE INFORMATION CARD. |
