Mystery Noise

[Les Smith]

Hi, Dave.

My guess is that your problem is with the bushing. Yes, you can replace
just one without having to remove the whole rail, although you're obvious-
ly working in tight quarters. After removing the damper, the old bushing
should be easy enough to remove. You might find it easier to feed the new
piece of bushing cloth through from the bottom than the top. If a pair of
long tweezers won't do the job, you might try a pair of EXTREMELY FINE
long, needle-nose pliers to pull the bushing cloth into position. After
it's dried you can trim it with an "Exacto" knife with a narrow blade.
Putting a longer "point" than usual on the end of the bushing cloth,
should facilitate pulling it into position. When doing this job, bad
language IS allowed!

Les Smith
leswsmith@buffnet.net

On Tue, 14 Oct 1997, Vanderhoofven wrote:

> 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
> 
>