<!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>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></FONT></BODY></HTML>