<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=windows-1252" = http-equiv=Content-Type> <META content="MSHTML 5.00.2919.6307" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#d8d0c8> <DIV><FONT size=2>From time to time the subject of gluing up = soundboard panels in the small shop comes up. One of the difficulties encountered is that = of machining the finished panel smooth and flat to some particular = thickness. This process is exacerbated by a characteristic of spruce (well, all woods to = some extent--it's just a bigger problem in spruce) called = "slope."</FONT></DIV> <DIV> </DIV> <DIV><FONT size=2>When trees start to grow as seedlings they do so = with a severe twist, as much as 45º in some trees. They do this for survival--their = tiny little trunks do not yet have the strength to withstand the ravages of = wind and storm. Or the occasional stomping of an otherwise friendly grizzly. This = twist gives the little tree trunk the flexibility it needs to survive and = grow. Over the years this twist straightens out and, ideally, the tree grows = straight and true. Often, however, this twist will reverse itself just a bit giving = rise to the characteristic of slope in lumber cut from the tree. </FONT></DIV> <DIV> </DIV> <DIV><FONT size=2>In most species commonly used by man for his various = endeavors this is not a serious problem. It is, however, a serious problem for the = woodworker attempting to hand-plane a glued-up spruce = panel.</FONT></DIV> <DIV> </DIV> <DIV><FONT size=2>All of this introduction is to say that there is a = good article on the subject in the current issue of WoodenBoat Magazing (#172--May/June 2003). Written by an instructor at the Northwest School = of Wooden Boat Building in Port Townsend, Washington, it deals mostly with = white oak being prepared for steam bending but the principles apply to all woods</FONT></DIV> <DIV> </DIV> <DIV><FONT size=2>Del</FONT></DIV> <DIV> </DIV> <DIV><FONT size=2>Delwin D Fandrich<BR>Piano Designer & = Builder<BR>Hoquiam, Washington 98550 USA<BR>360.532-2563<BR>360.532-6688<BR><A href="mailto:pianobuilders@olynet.com">pianobuilders@olynet.com</A></FO= NT></DIV></BODY></HTML>