Slick Key Bushings.

Richard Brekne Richard.Brekne@grieg.uib.no
Fri, 05 Apr 2002 14:42:06 +0200


Hi list.

Newton is always on about the need to polish key pins, and I have a
story to relate that underlines the importance of as slick as possible a
relationship between key pin and bushings.

The other day one of the professors at the UiB came up and complained
about the friction of the keys on the two S&S C's we have in the concert
hall. Now one of these instruments I had just done a basic Stanwood job
on and in that process had taken pains to polish both the balance rail
and front rail pins, and to coat them with CLP. This instrument was not
as bad as the other, according to this professor, but both were far from
optimal and he proceeded to demonstrate what he meant.

He showed me that pushing a bit sideways on the key whilst pushing
downwards revealed a lot of friction. So I started checking it out by
over emphasizing the sideways component of depressing a key and found
that there was actaully quite a bit of drag there. Not immediately
knowing what the cause was I told him I would see what I could do.

I took the worst of the two and removed the action, top action, and
started looking at the key bushings. They were a bit worn, and I was
aware of that before hand. There was also a blackish buildup of some
combination of dirt dust and corrosion from the pin. So I decided to
just try and add a couple drops of CLP to each bushing and also re coat
the pins.

The affect was astounding.  We normally think when we play that it is
just a downward motion of the key we are dealing with.... but this
experience has demonstrated better then any other I have had that there
is much more to it then that. The action feels and plays like silk
compared to how it felt before this treatment.

I waited a week to see if it would last at all, found it did and did the
same thing to the other C. In both cases I will have to replace the
bushings sometime in the near future anyways... but I think I will give
them a drop or two of CLP when I do.

Anyways... the professor hunts me down today at lunch, he had just
gotten done useing one of them and just had to tell me how unbelievable
the difference was. He was right.... I still am very much suprised at
how much a difference was made.

So listen to Newton and his "polish the darn Key pins" line.  I for one
have learned not to underestimate the value of the least possible
friction (of any kind) between key pins and bushings.

RicB



--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html




This PTG archive page provided courtesy of Moy Piano Service, LLC