key pins

[Dave Nereson]

----- Original Message -----
From: Ron Nossaman <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: Monday, March 11, 2002 10:47 AM
Subject: key pins


> Well, since there doesn't seem to be a bunch of enlightenment on laminated
> knucklebones pouring in, I've got another annoying question I was holding
> in reserve for just such a situation.
>
> Are there any detectable differences in performance, longevity, bushing
> abuse, or competitor envy between brass, plated brass, or plated steel key
> pins? Why not nickel silver, stainless steel, or Kryptonite? With center
> pin composition being of such concern, it seems that key pin composition
> cults would be inevitable too. I admit I haven't had to repin more than a
> couple of keys as field repairs in all these years, so maybe that's it. No
> one notices any difference. Still, it seems odd that no one champions or
> outright condemns specific key pin materials in either advertising or
> technical literature. Or do they?
>
> Ron N
>
    Probably the only time it makes much difference is,  a) with much wear
or age or,  b) in climates where corrosion occurs easily, either from
pollution or salty air or ???.  I suppose this would also be influenced by
any "stuff" the factory treats the bushing felt with, or just natural
reactions the cloth and its ingredients have with the plating on the pins,
and of course by any lubes added by technicians over the years.  I've seen
vertigris on keypins, too, especially the old ones that have a small oval
tip in the key button that's a different diameter from the rest of the pin,
but what caused it, I don't know.  Have seen some keypins corroded so badly
that when removing keys, they bind so tightly in the key button that they
pull the pin out of the balance rail!  Have noticed that the worn spot on
older pins is brass-colored, with the rest of the pin being nickel-plated, I
assume.

  >>  Still, it seems odd that no one champions or
> outright condemns specific key pin materials in either advertising or
> technical literature. Or do they?<<

    By the time the pins corrode and affect performance, the piano is an
"older model";  the new ones won't have their pins corrode for decades,
probably, so it's not a concern in advertising.  Unless, as above, the
climate causes premature corrosion.

    Regarding key buttons, I like to see hardwood ones on new pianos, but
will admit (complain) that they're hard to ease -- I know, you're sposeta
squeeze the bushing cloth, not crush the wood, but sometimes the bushing
cloth is already as squoze as possible and the pin is still tight.  If it's
already thin cloth, what do you do, go ahead and try to crush the wood a
little?  iron the cloth?  burn it even thinner?  take out the cloth, file
the wood down and rebush?   -- David Nereson, RPT, Denver