dampers

[Paul McCloud]

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You might check to see if the damper timing is correct.  If the dampers lift too soon, the dampers are going to rest partly on the spoons and allow leakage.  You might also check the overall regulation.  The keybeds on those things are liable to warp, causing the regulation to go out.  Is the cabinet in good shape?  Glue joints?  Separation of back posts, ect?  These Kimballs ('70's vintage) were really junky.  I'm guessing this is your vintage, no?  Any regulation problems are going to upset the dampers.  
Even if the dampers appear to be in good shape, you may need to replace them.  They get "used" to being in one spot.  Are they flat-straight across, or do the edges of the felt go beyond the string plane?  After many years pressing against the strings, they will become misshapen.  Try plucking the strings individually, and see which ones are leaking.  You may need to replace these.  See if the strings are spaced properly and evenly.  You may not be able to make them all line up evenly, because of the screws in the pressure bar.  If you did some string alignment before you had this problem, it may have forced the string into a different "groove" in the damper and caused it not to dampen.  If your problem is in the trichord wedge section, varying the string separation a little bit to allow all 3 strings to contact the wire may help.
What about the spring tension on the dampers?  Do you have a good amount of pressure?  See if a little help from your finger or tool will quiet down the notes.  Corrosion on the springs will weaken them.
If you did some adjustment of the lost motion, or moved the hammer line, turning up the capstans will make the wippen spoons contact the dampers sooner (see above) and cause leakage.  Maybe someone before you did some work on it, and he/she didn't fix the problem, or screwed it up without knowing what they were doing.   
I hope this helps.  Good luck!  (Don't you just love damper work?)!
Paul McCloud
San Diego


----- Original Message ----- 
From: Ed Carwithen 
To: pianotech@ptg.org
Sent: 10/17/2004 10:58:11 PM 
Subject: dampers


I am having trouble eliminating the after ring in the strings of a Kimball upright.  I noticed a ring before I started work on it.  The bass strings have now been removed and sent off for duplication so it can’t be a problem with bass overtones.  I have done regulation on the middle and treble, but there is a significant ringing in the strings.  The non speaking sections of the strings do have ribbon felt on them.  The dampers are in good shape and seat well on the strings.  When the strings are depressed the dampers do follow.  The pedal is not pressing the dampers off the strings.  I have damped off all of the strings except one to try to isolate one note at a time, but there is still ring.  I don’t know what to try next.  Any suggestions?
 
Ed Carwithen
John Day, OR
 
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