<!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 5.00.2920.0" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>Oops...  My email was delayed, due = to an internet problem.  My question about grinding the capo had = already been answered.  However, what about the magnetic hardening?  = This is usually done with higher tech alloys, not gray cast iron.  But can = it be done with cast iron???  </FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>Regarding the prospect of setting a = steel rod in a groove ground in the capo...  What dia of rod?  Also, is = spring steel the best choice -- i.e. like piano wire?</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>Peace,</FONT></DIV> <DIV><FONT face=Arial size=2>Sarah</FONT></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:sarah@gendernet.org" = title=sarah@gendernet.org>Sarah Fox</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> Saturday, January 25, = 2003 1:27 AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Capo Hardening, = was: Tuning problems under capo bar</DIV> <DIV><BR></DIV> <DIV><FONT face=Arial size=2>I've wondered about this = myself.  My Wissner's capo is very badly grooved.  I've shifted some of the = strings slightly to eliminate their "zinging," but the capo will obviously = need reshaping.</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>As far as I'm aware, different metals = are hardened via different methods.  However, the fact remains that = this usually involves heating and cooling for various periods of time -- = something that's hard to do with something as large as a harp -- and difficult = to do without stressing the metal and risking a crack.</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>I believe some ferrous alloys are = hardened with magnetic fields, perhaps with moderate heating.  Perhaps this = could be a useful alternative?  I have no idea how this is done, though.</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>Alternatively, does anybody ever = grind the original capo off and overlay a hardened bar, fitted for height?  = It could be epoxied in place for a tight mechanical contact.  Of = course this begs the question of what happens when a capo is ground and filed and = ground and filed and ground and files -- until the downbearing is = inadequate.  Yes, I know the plate can be lowered, the bridge can be built up, the = aliquot plates can be filed, etc., but does this ever present a problem, such = that a technician might decide to rebuild a capo?</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>Peace,</FONT></DIV> <DIV><FONT face=Arial size=2>Sarah Fox </FONT></DIV> <DIV><FONT face=Arial size=2>(Columbus, Ohio)</FONT></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:kevin.e.ramsey@cox.net" = title=kevin.e.ramsey@cox.net>Kevin E. Ramsey</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, January 24, = 2003 8:27 PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Capo Hardening, = was: Tuning problems under capo bar</DIV> <DIV><BR></DIV><FONT face=Arial size=2> <DIV>Hello Ron. I there anything you can tell us about hardening the = capo. I've seen you write about that before. Is this something you do in = your shop? Do you do it to all pianos? Do you have a method of testing = the hardness of the capo? Am I asking questions that have already been = answered? Thanks. </DIV> <DIV> </DIV> <DIV>Terry Farrell </DIV> <DIV> </DIV> <DIV>    Terry, I don't know about Ron, but I've = thought about it, and I don't see how you could harden the capo. I hope I'm = wrong, but you hard, or temper a metal by heating it until it glows for a = certain amount of time, and then you quench it in either oil or water. The = plate is going to act as a gigantic heat sink, not allowing the metal to get = to the proper temp, and you'd have trouble quenching it even if you did. = When you heat a metal and allow it to cool by itself, it's called annealing, = and it softens the metal. Others can tell me if I'm all wet, but that's how = I understand it. </DIV> <DIV> </DIV> <DIV>    Kevin E. Ramsey</DIV></BLOCKQUOTE></BLOCKQUOTE></FONT></BODY></HTML>