In the 130422 MMDigest, Vince Wukmir offers to the list, his surplus
of garment leather to be used as gasket material.  Specifically, he
mentioned Ampico and Simplex valve gaskets to be made from this
material.

When I lived in the Chicago area, one of my mentors was Dave Ramey.
He introduced me to the use of garment leather in player piano
rebuilding.  While my efforts were primarily reproducing pianos, he
specialized in nickelodeons.  Some of the garment leather wholesalers
were on Wabash Avenue.  The leathers were displayed on skids, on the
second floor.  Most were slick finished on one side, with the other
side suitable for gluing.  Some were "suede" on both sides.

Most of the expert instrument rebuilders in Chicago used leather
from the garment industry.  Nickelodeon pumps were covered with slick
black leather on the outside after the inside was coated with PVC-E
glue (this was just one technique), but I could never bring myself
to change the original pneumatic cloth on an Ampico pump to leather,
nor could I bring myself to change from cork gaskets to leather in
the restoration of an Ampico valve.

I learned early in my career that one must be very stingy with air
leaks in the Ampico.  The Ampico pump was barely large enough to make
the system work properly.  On the other hand, Aeolian's Duo Art pump
had a much greater capacity and thus, the system was more forgiving
to a few tiny losses in vacuum.

When the revolution and rediscovery of pneumatic players gained momentum
in the 1960's, the performance of the original valves was adequate and
they did not need to be rebuilt.  Later, in the 1980's, it was obvious
that valves had to be rebuilt, too.  Soon it was discovered that if
everything was restored and airtight, the reproducing instrument had
more potential then ever imagined in 1960s.  Up until that time, it was
assumed that leather was tight enough.

When I got involved during the 1970's, I discovered that leather always
leaks -- there is no such thing as air-tight leather!  That lead to
my experimentation with other valve materials.  Soon I discovered that
Ampico valves could be rebuilt with 100% airtight sponge neoprene valves,
but the player community showed little acceptance for that advance; bad
experience with cheap sponge used in modern Aeolian players and others
ruined the acceptance of the new product that I advocated.  The sponge
that I had manufactured into Ampico valves, over 30 years ago, is still
supple and 100% air-tight, but that is another story.

Knowing that leather always leaks, I adopted the philosophy that it is
okay to have leather valves if they are tight as the originals but it
is not okay to use leather as a sealant where it was not used originally.
That is the point of this post.

Ampico never used leather gaskets.  Leather gaskets always leak to some
degree.  Original cork gaskets used in the Ampico do not.  Why degrade
the already challenged Ampico pump by introducing more leakage than
what the original system had?

In all fairness, leather gaskets are widely used in the pipe organ
business and also in the player business.  My point is that if a system
didn't use them originally, don't change now during a restoration
because it may introduce more leakage than the system can handle.

By all means, use the leather offered by Vince Wukmir where appropriate.
I don't recommend the leather as Ampico valve gaskets -- stick to cork
or even better, the newer, high quality, cork-neoprene material that
will last forever.

Bob Taylor
Missouri