termination & differences in string pull/pin set

[McNeilTom@aol.com]

Hi, Rolf, and Colleagues -

The Baldwin SD-10 and SF-10 have used 'treble terminators' (Baldwin's
terminology, although in this thread some have referred to them as
'resonators') for more than 30 years.  These are the proprietary castings used
in what would otherwise be the 'capo' area.  There have been some changes in
design and materials over that time.  The earliest version, as I recall, were
cast as gang units serving several notes.  More recent ones are individual
castings for each note.

Willard Sims was the head of Baldwin's technical service department in the
early '70s (and for some time before and after that).  He used to advise field
techs to lubricate these fittings with WD40 "once every few years".
Apparently, at that time anyway, the castings were of a composition that did
not provide a lubricious contact with the steel strings.  (By contrast, the
contact between the steel strings and the brass agraffes _is_ lubricious.)
Willard's instructions were to apply a small amount of the WD40 at the two
contact points (the actual termination point, and the string support closer to
the tuning pins) using a Q-tip.  Then wipe dry with a Kleenex.  The minute
amount of lubricant remaining would be sufficient.  I did this with a few
pianos in my care at that time, and I liked the resulting feel in tuning them.
I noticed no ill effects at all, except a slight tendency for the lubed
strings to collect dust.  I have not employed this technique in a number of
years somehow.  However, I have three SF-10s and one SD-10 that are candidates
for the treatment.

Rookies, take note:  If you don't know what you are doing, or are not careful,
you may wish you'd never heard of WD40!  For heaven's sake, do not spray the
stuff anywhere around a piano.  And don't put it anywhere Willard didn't tell
us to.  In particular, do not get any at all on any wound strings!

      -   Tom McNeil   -
Vermont Piano Restorations


In a message dated 99-03-07 10:14:19 EST, Rolf von Walthausen wrote:

<< The specific situation I'm trying to figure out has to do with a Baldwin
 SD-10 from the early 70s that was restrung five years ago with the original
 'treble resonators'.  Nothing else was modified as far as I can see.  The
 problem is that the strings in the treble section D5-G6 do not move in
 corresponding units with similar movements of the pin.  The feel and
 response is much like that of a Steinway upright where the string moves a
 large amount all of a sudden after many movements of the pin in the block.
 I've never experienced this before on an SD-10, either with the old-type
 resonators or the new type.  I was interested to read Roger Jolly's
 observation that the 'old-type' resonators were made of a material with a
 different carbon content and hardness, so I wonder if there were
 experiments with different prototype models of SD-10 (between the SD-10 and
 SD-10b) with resonators that might be causing the strings to respond
 differently to string pulls?  >>