Hi All, I've been stimulated by some private correspondence to explain
my strong attitude concerning the use of leather for the bellows in an
Ampico rotary vacuum pump. (I'm not saying that I was asked to explain.
Their letters merely stimulated me.)
In a nutshell, (a) leather is available in an infinite number of
thicknesses and grades, (b) there are (to my knowledge) no published
reports or technical articles which extol the virtues of leather over
the original quality bellows cloth used when the pump was made, and,
(c) no one (to my knowledge) has established guidelines for selecting
the "best" leather for the job. Is kangaroo leather the only leather
that works better than good-quality, heavy-weight bellows cloth? How
thick is "just right"?
Given these unknowns, it seems to me unreasonable to advocate leather
as the "preferred" material for recovering the bellows. And that's
why I expressed a strong attitude.
Granted, there have been and will be times when good-quality 'standard'
(other subjective words) rebuilding materials are not readily available.
I, for one, will always do what I have to to complete a job in the
'best' way possible. And I'm not ashamed to admit that I've used
non-standard materials when I felt confident that the end result would
exceed the original specifications. I've even gone as far as to use
non-standard materials on a customer's piano with the proviso that if
it failed prematurely, I would rebuild it again for free.
But if what is "preferred" is not 'standard', don't we owe it to future
generations to change the standard? Rewrite the books? And lay down
some new guidelines?... First?!
John A. Tuttle