Scanning Electron Microscope

[Ron Torrella]

On Sat, 11 Feb 1995, stanwood wrote:

> I have easy access to a scanning electron microscope.
>
> RE: damper noise, I was thinking about looking at the surface of music wire,
> untreated, and treated with different polishing techniques.
>
> If anyone has any other ideas for piano tech related SEM studies,
> let me know what they are.  I'll see what I can do.

How about looking at the damper felts (offending ones that make excessive
noise) to see if there's any kind of buildup -- and perhaps try to figure
out what the buildup is.

I made an interesting discovery several years back on a Steinway B.  The
customer bought a used intrument in another state, brought it home and
complained about the *really* loud "shhh-uh" noise (how's that for a
description!) she could make and actually play a tune or two --
audibly!--without the hammers ever hitting the strings.  Bizarre.  I
couldn't detect any crust to speak of on the damper, so I turned to the
string to see if there was something there.  When I removed the dampers
(a few at a time) I noticed that the strings were discolored under the
dampers -- only.  The only possible explanation was dirty felt.
Apparently is was a "run" that hadn't been cleaned very thoroughly, so
body oils from the "donor" left an imprint on the strings.  It was bad
enough that even polita wouldn't get rid of the noise.  The strings were
actually pitted and had to be replaced.  I'm convinced that the previous
owners used the piano as furniture, period.  Nobody could possibly play
that instrument seriously and enjoy it.

Ron Torrella                  Self-explanatory - [A]bort [C]ancel [R]etry
University of Illinois              Inexplicable   -   + + +