Mystery Noise

[Lance Lafargue]

David,
Yes, you can rebush the individual guide-hole.  I usually rebush, then
place a bridge pin in (a few thousands of an inch larger than the wire) the
hole, treat with methanol and water to sized the hole(hair dryer on low
speeds this up).  I sometimes put a drop of Protek on the bushing to be
sure there is no friction.  Smooth out the wire with still wool or scotch
brite if you need to.  I have found noise from the under lever spring to be
a problem occasionally.  Getting to it is tough sometimes. Check the tray
pins on the ends of the tray, etc.  The noise may be from any of the wires
touching bare wood in the guide rail, or touching an adjacent string.  Does
it rattle when the sustain pedal is depressed?  Did you get my personal
e-mail to you the other day?  Hope this helps.

Lance Lafargue, RPT
New Orleans Chapter
Covington, LA.
lafargue@iamerica.net

----------
> From: Vanderhoofven <dkvander@clandjop.com>
> To: pianotech@ptg.org
> Cc: M E F <yeaferrell@getonthe.net>
> Subject: Mystery Noise
> Date: Tuesday, October 14, 1997 11:06 AM
> 
> Dear Friends,
> 
> I have a mystery noise that is baffling me and irritating my customer.
> 
> The piano in question is a small, older Osborne grand.  The hammer shanks
> have no knuckles, instead they have leather covered "bumps" on the hammer
> shank.  Also, the wippens have brass billings flanges instead of wooden
> flanges.  This piano also does not have a una corda pedal or sostenuto
> pedal. Instead, the keyframe is screwed down to the keybed and the left
> pedal lifts a rail that raises all of the hammers closer to the strings
> (similar to the way an upright piano soft pedal functions).
> 
> The mystery noise is like a rattle, and is located in the first note past
> the bass/treble break - note A#2.  Although the overall "noise" level of
> this action is rather high, this particular noise ("rattle") is not in
the
> key, wippen, hammer, shank or flange.  The noise is not from the
soundboard
> or ribs or any loose case parts.  After inspection with a small mirror
and
> light, there does not appear to be anything laying on the soundboard that
> would make a rattle like this.  The noise is isolated to the damper
> underlever, wire and damper head.  The damper underlever flange screw is
> tight, the screw that secures the damper wire into the underlever is
tight,
> and the damper wire is tight in the damper head.
> 
> Possibilities...  The two small leads in the underlever were slightly
> loose.  Whereupon I promptly swedged them, splitting the wood of the
> underlever.  (Oops!  My mistake.  I know, I know, I can't afford to
> purchase a pair of the Renner DeadLeader pliers yet.)  Once the
underlever
> was reglued with Titebond II and the leads were secured, that did not
seem
> like the cause of the noise because the noise is still there. 
> 
> One other possibility:  This note right past the bass/treble break has
the
> damper head offset quite a bit because of the plate strut. The damper
guide
> rail bushing is worn out and the wire has a lot of loose play.  The
damper
> head and wire do vibrate quite a bit when the key is played, but the
rattle
> is not caused by the wire or damper head touching the plate, the adjacent
> damper head and wire, or any of the strings.  I do believe that the noise
> is coming directly from the contact of the damper wire with the worn out
> guide rail bushing.  Lubricating the damper wire has little to no effect
on
> the noise.
> 
> Question:  Is it possible to rebush an individual damper guide rail
bushing
> with the rail still in the piano?  Removing the guide rail and rebushing
> the entire rail is out of the question because of the quality of the
> instrument.
> 
> Suggestions are welcome, and will be forwarded to my customer who is also
> on the Internet.  If you don't want your answer forwarded to my client,
> please let me know and I will respect your privacy.
> 
> Thanks for your help!
> 
> David
> 
> 
> David A. Vanderhoofven, RPT
> Joplin, Missouri, USA        
> e-mail:  dkvander@clandjop.com
> 
> web page:  http://www.clandjop.com/~dkvander/
> #pianotech page:  http://www.clandjop.com/~dkvander/ircpiano.html
>