[CAUT] S&S Key Bushings

[Jim Busby]

Thanks Fred,

I forgot about the Teflon in the bushings. Do you do that very last?

Jim

-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Fred Sturm
Sent: Thursday, October 30, 2008 12:31 PM
To: College and University Technicians
Subject: Re: [CAUT] S&S Key Bushings

On Oct 30, 2008, at 10:31 AM, Chris Solliday wrote:

> I would not recommend using heat in general with sizing solutions
> although
> some glues can take it and the heat may provide a quicker process
> overall.


Hi Chris,
        Thanks for the info about VS Profelt and its ingredients. I have
ordered some, and will see how it compares with my own "standard
method" - which does use heat. I agree that use of heat may cause
problems if you aren't careful, but as long as you are paying
attention it can be done safely  (a little experimentation with one or
two keys will reveal potential problems).
        I posted about my method a few years back, but maybe I should do a
quick repeat. Briefly, keys off the frame, in Spurlock clamps. Apply
steam as if removing bushings, but only enough to expand the felt
(keep the travel steam iron moving, keep your eye on the condition of
the bushings). Follow immediately with heated caul (temperature
controlled). A very quick (half second or less) plunge into each
mortise to press the felt flat, followed by going back through the set
a little slower (up to one second). This both dries and irons/fits the
felt, and, in my usually dry climate, I can essentially put the keys
right back on the frame the same day (after doing other tasks like
brushing and lubing knuckles, scuffing hammer tails, etc). I have
found that one second of a caul in a mortise doesn't cause problems of
glue wicking into felt and the like.
        Whatever we do to re-fluff the felt, I think lubrication is really
the key to longevity. All my keypins get McLube, all bushings get
powdered teflon. The difference in longevity is very obvious over a
period of years. Thanks to Newton Hunt for pushing that point
repeatedly. Polished, un-nicked, lubricated pins + well-fit,
lubricated, ironed bushings = nice feeling keyboard for a long time,
even with heavy wear. [Attention to fine detail = better results in
general.]

Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu