<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=iso-8859-1" = http-equiv=Content-Type> <META content="MSHTML 5.00.2919.6307" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#d8d0c8> <DIV> </DIV> <BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A href="mailto:mfarrel2@tampabay.rr.com" title=mfarrel2@tampabay.rr.com>Farrell</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = href="mailto:pianotech@ptg.org" title=pianotech@ptg.org>Pianotech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, April 11, 2003 = 4:36 AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Soundboard Torture = - and Understanding!</DIV> <DIV><BR></DIV> <DIV><FONT color=#008000></FONT> </DIV> <DIV> </DIV> <DIV>> I was debating with myself as to whether or not I should = warn you about<BR>> this, ultimately deciding that experience is a really = great teacher and you<BR>> weren't jeopardizing any priceless pianos on = your road to discovery. You can<BR>> use a spruce panel as a humidity = indicator but you have to allow it to<BR>> free-float. I.e., you cannot allow it = to come under compression.</DIV> <DIV> </DIV> <DIV><FONT color=#008000>Gee whizz. Nice guy! It was a very good = educational experience. Now how can you free-float a gauge? The only way I = can imagine that is to not put a rib on it, and simply measure the change = in length across the grain. Is that what you have in mind?</FONT><BR></DIV></BLOCKQUOTE> <DIV><FONT size=2>Ah, but Grasshopper, what you learn by doing will go = into your being with much more clarity than what you learn by = reading.</FONT></DIV> <DIV> </DIV> <DIV><FONT size=2>As to my idea of a wood-based humidity = indicator--think in terms of levers.... Multiply that motion. (All of which is the sneaky = way of saying I can't find the appropriate drawing or picture in my new = computer. Soon! Real Soon Now!)</FONT></DIV> <DIV> </DIV> <DIV> </DIV> <BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV> > Yes, what you are witnessing is 'compression set.' = This phenomenon takes<BR>> place any time wood cells are placed under compression and are particularly<BR>> observable when the = compression is applied perpendicular to grain. </DIV> <DIV> </DIV> <DIV><FONT color=#008000>I be a believer! I be seen it with my own eyes!</FONT></DIV> <DIV><FONT color=#008000></FONT> </DIV> <DIV><FONT color=#008000>This quickly brings to my mind the sight of = several semis full of (compression-crowned-type) new pianos for a local = "University Sale" that sat for a week in a blacktop parking lot in Tampa Florida = in the full sun during the hot monsoon month of July. Not a pretty thought.</FONT></DIV> <DIV><FONT color=#008000></FONT> </DIV> <DIV><FONT color=#008000>Is it possible this had anything to do with = the negative 1/4" of crown in MY new "famous NY manufacturer" piano?</FONT></DIV></BLOCKQUOTE> <DIV><FONT size=2>Partly, yes.</FONT></DIV> <DIV> </DIV> <DIV> </DIV> <BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV><FONT color=#008000></FONT> > Keeping a piano with a compression-crowned soundboard in a hermetically<BR>> sealed = environment would not relieve the problem unless the atmosphere in<BR>> the hermetically sealed environment were maintained at such a level as = to<BR>> keep the soundboard panel at 4% MC.</DIV> <DIV> </DIV> <DIV><FONT color=#008000>Does a semi in an August Florida monsoon = meet this criteria?</FONT></DIV></BLOCKQUOTE> <DIV><FONT size=2>I don't know. What are the numbers?</FONT></DIV> <DIV> </DIV> <DIV><FONT size=2>Del</FONT></DIV></BODY></HTML>