<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 5.50.4134.100" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>I have more problems with clamping = while gluing without having to worry about making two mismatched pieces of wood = conform to each other during the gluing process.</FONT></DIV> <DIV><FONT face=Arial size=2>Since the bevel doesn't matter much to = the performance of the board, i<FONT face=Arial size=2>n my lame way of = thinking, the bevel on the rim should match the board when it is in the unstressed = position. A great glue joint here seems to be = essential.</FONT></FONT></DIV> <DIV><FONT face=Arial size=2>Of course Del probably has the = pneumatic sound board, (push one button, come back tomorrow), clamping system that will = flatten any piece of wood. For the ultimate in gluing systems.</FONT></DIV> <DIV><FONT face=Arial size=2>Keith R</FONT></DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=pianobuilders@olynet.com href="mailto:pianobuilders@olynet.com">Delwin D Fandrich</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">Pianotech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, November 23, = 2002 11:33 PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Belly rail crown - = Why???</DIV> <DIV><BR></DIV> <DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=Erwinspiano@aol.com href="mailto:Erwinspiano@aol.com">Erwinspiano@aol.com</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> November 23, 2002 10:14 = PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Belly rail crown = - Why???</DIV> <DIV><BR></DIV> <DIV><FONT face=arial,helvetica><FONT lang=0 face="Times New = Roman" size=2 FAMILY="SERIF">In a message dated 11/23/2002 10:00:34 AM Pacific = Standard Time, <A = href="mailto:pianobuilders@olynet.com">pianobuilders@olynet.com</A> writes:<BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" = face="Times New Roman" color=#000000 size=3 = FAMILY="SERIF"><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face="Times New = Roman" color=#000000 size=3 FAMILY="SERIF">Del<BR>....Recognizing = that by in large most on the list are building rib crowned boards that retain more of = there crown when under load than the former compression stlye boards. Rib = crowned boards being much stiffer by design,  thanks to higher rib = radii and stiffer spruce rib material (formerly sugar pine) and deeper = ribs.... </FONT></FONT></DIV></BLOCKQUOTE> <DIV><FONT face=arial,helvetica><FONT lang=0 = style="BACKGROUND-COLOR: #ffffff" face="Times New Roman" color=#000000 size=3 = FAMILY="SERIF"><FONT face="Comic Sans MS" color=#000080>They don't necessarily start = out that way. While the rib-crowned soundboard certainly has the potential of = greater stiffness -- there is always the option of more and taller ribs -- in = practice I'm not sure they start out all that much different. A well done compression-crowned soundboard can be quite stiff indeed. But it may = not keep that stiffness very long. It's in holding the long term stiffness that = the rib-crowned soundboard comes out ahead. </FONT></FONT></FONT></DIV> <DIV><FONT face=arial,helvetica><FONT lang=0 = style="BACKGROUND-COLOR: #ffffff" face="Times New Roman" color=#000000 size=3 = FAMILY="SERIF"><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <DIV>    I see nothing wrong with the beveled rim = personally, if my boards are retaining a good amount crown even when strung I = see no reason to induce another unnecessary possible strain at the edge of = the board by changing all the beveled rastens that come through the shop = to a flat edge. No, I'm not saying you were advocating that either.</DIV></BLOCKQUOTE> <DIV><FONT face="Comic Sans MS" color=#000080>Well, I don't know = that there is all that much wrong with the practice. I'm mostly just not convinced = it does much good. </FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"><FONT face="Comic Sans MS" color=#000080></FONT> <DIV>    Simply clamping a piece of spruce to a bench = and bending it isn't exactly like the continuos rim of board being glued = to a curving rim. Gluing the board to the rim gives the whole structure a = cohesive stiffness it doesn't have before that. </DIV></BLOCKQUOTE> <DIV><FONT face="Comic Sans MS" color=#000080>Come on, Dale, you = know better than that. Sure, gluing the board to the rim makes it act like a = clamped-edge diaphragm, but wood is still awfully thin wood and it still bends = under load. Especially so when the load is essentially across-grain and most of it = is along the bent side or at roughly a 45º angle as = most of it is along the bellyrail and the straight side. And along the bass curve, = well, who cares?</FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <DIV>   Also the board is often thinned down to as little = as .250 at the edges so undue stress once again not desired. The 1 and 1/2 = degerees typically found in the rim joint could as practicallity or = compromise be reduced to half that and this angle would more likely conform to the = residual crown angle after stringing.</DIV></BLOCKQUOTE> <DIV><FONT face="Comic Sans MS" color=#000080>And, that's pretty = much my point.  </FONT></DIV> <DIV><FONT face="Comic Sans MS" = color=#000080></FONT> </DIV><FONT face="Comic Sans MS" color=#000080></FONT> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"><FONT face="Comic Sans MS" color=#000080></FONT> <DIV>   Perhaps  petty, lame and faulty thinking but = it's mine all mine.</DIV></BLOCKQUOTE> <DIV><FONT face="Comic Sans MS" color=#000080>Yup. Lame it is. And = you can have it. Unless it's already there in which case I'll have some too.</FONT></DIV> <DIV><FONT face="Comic Sans MS" color=#000080></FONT> </DIV> <DIV><FONT face="Comic Sans MS" color=#000080>Del</FONT></DIV></BLOCKQUOTE></FONT></FONT></BODY></HTML>=