>
>I'm told it's a corrosion thing. The center pin plating apparently lets go
>of the pin and jams up, and contaminates, the bushing.
>
>Ron N
Hi Ron,
Some vintage's, and mfg's of pianos, the plating was
serious problem that reared it's ugly head 3 or more years down the road
depending on climate. Yamaha under levers from about 15yrs ago have been
giving problems around here for the last few years. Strange thing it's
just under levers.
The second cause has been the incorrect application of graphite to the
bushing cloth. Recently finished doing an investigation for
S.M.C. Pleased to announce the graphite is now gone from current
production. The grade and type of application of glue and graphite to
bushing cloth is one of the highly critical elements in production.
All the various samples that I have examined, have had scoring problems
due to hard crystals in the graphite, this has in turn caused some flaking
on some plated pins. Samick on the other hand has been using stainless
steel pins and it has been purely a graphite/scoring problem.
Hope this shows a little light.
Regards roger
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