<!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 6.00.2800.1226" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY style="FONT-SIZE: 10pt; FONT-FAMILY: Arial; BACKGROUND-COLOR: = #ffffff" bgColor=#ffffff> <DIV><FONT face="Comic Sans MS" color=#000080 = size=3></FONT> </DIV> <BLOCKQUOTE dir=ltr 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> January 02, 2004 10:37 = AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: No downbearing = ?</DIV> <DIV><BR></DIV> <DIV>In a message dated 1/2/2004 8:41:36 AM Pacific Standard Time, <A href="mailto:pianobuilders@olynet.com">pianobuilders@olynet.com</A> writes:</DIV> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px = solid"> <BLOCKQUOTE dir=ltr 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=mailto:Erwinspiano@aol.com href="mailto:Erwinspiano@aol.com">Erwinspiano@aol.com</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=mailto:pianotech@ptg.org href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> December 31, 2003 = 5:56 PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: No downbearing = ?</DIV> <DIV><BR></DIV></BLOCKQUOTE></BLOCKQUOTE> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px = solid"> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 = size=3>At least until the transition from hot animal hide glue to "modern" synthetic adhesives (for this industry this took place between roughly the = mid-20s to the mid-30s) all pianos, grand or vertical, had at least some amount = of compression-crowning. This is regardless of what curve may or may = not have been machined into the ribs. Of manufacturing necessity the = soundboard panels were heated to approximately 120º F for several hours = before ribbing. It was long enough to thoroughly heat the panels and dry = them to some very low moisture content -- and, hence, shrink them -- prior = to ribbing. By definition this is = compression-crowning.</FONT></DIV></BLOCKQUOTE> <DIV><FONT face="Times New Roman" color=#000040>  <FONT size=3><STRONG>>> I have no doubts</STRONG></FONT> = <STRONG><FONT size=3>that there was some sort drying prior to ribbing but with the = uprights a mere few hours of heating isn't really going to = take a soundboard panel to an adequately low emc level for compression = crowning. None of us would expect that result in our own shops. = </FONT></STRONG></FONT></DIV> <DIV><FONT face="Times New Roman" color=#000040><STRONG><FONT size=3>   I suspect any amount of crown achieved was = mostly dependent on circumstance I.E. it was a cold dry time of year = & the pre ribbed boards were already at low emcs. </FONT></STRONG></FONT></DIV></BLOCKQUOTE> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 size=3>Few = of us run soundboard conditioning rooms at anything like the temperatures used by = these early pianomakers. We certainly don't. You put a batch of already = reasonably dry and properly stickered soundboard panels in a room running well upwards = 120º+ and they are going to shrink quite nicely overnight. All you need to do = is get them down to 4%. Standard practice, I'm afraid.</FONT></DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 = size=3></FONT> </DIV> <DIV dir=ltr><FONT face="Comic Sans MS" color=#000080 size=3>Del</FONT></DIV></BODY></HTML>