Welcome Joe, The "prepared piano" as they call it here at UNL is a pain in the @$$^$%#.!!  Students not only put stickers on the damper heads, but also Sharpie pens and chalk marks, even on the strings, pluck with oiley fingers, quarters, paperclips, staples, screwdrivers, and try anything to get "the right sound"! This gives you lots of practice removing objects from the soundboard and action and keybed!  Unless you're able to teach the instructors on removal of foreign "stuffs" and insist they pass the info to the students, you're out of luck on them not damaging things. Strings and agraffes also get quite a bit of damage as well. Think of it as additional job security..... Personally, I'd like to put a nice tight hitchpin loop around the neck of whoever invented this "music"! 2.  Your second question sounds similar to capo problems in grands.  Perhaps, ( and the more experienced CAUT members will add to this) the agraffes have a termination point problem, either very sharp or quite flat.  It could also be weak string problem or very high tension design problem in Petrofs.  I'm not familiar enough on the tension scale of these pianos, but you might want to look that up as well. Just a couple of thoughts.... Best, Paul <table width=100%> <tr valign=top> <td width=40%>Joe Wiencek <jwpiano@earthlink.net> Sent by: caut-bounces@ptg.org 05/15/2007 07:55 AM <table border> <tr valign=top> <td bgcolor=white> <div align=center>Please respond to College and University Technicians <caut@ptg.org></div></table> <td width=59%> <table width=100%> <tr valign=top> <td> <div align=right>To</div> <td>caut@ptg.org <tr valign=top> <td> <div align=right>cc</div> <td> <tr valign=top> <td> <div align=right>Subject</div> <td>[CAUT] Agraffes and dampers</table> <table> <tr valign=top> <td> <td></table> </table> <tt>Hello list, This is my first posting to the CAUT list.  I have two questions 1:  How do you keep dampers free from damage when modern music requires playing the strings with fingers and the performers paste the damper heads with colored stickers, then remove them and tearing felt, etc. This is at NYU, but my own experience in music school tells me it must be all over. 2:  A  Petrof P131 upright with agraffes to the top has broken every   string from E6-E7.  The break is at the edge of the bearing before entering the agraffe on the speaking side. Any ideas? Thanks, Joe Wiencek jwpiano@earthlink.net tel: 551 358 4006 </tt>