It has always troubled me that a man's work on pneumatics is no better
than the material he used to recover them.  The claim that stock rubber
material deteriorates just sitting on your shelf is especially
troublesome.

Would this happen if manufacturers used the best rubber available, when
they make the cloth, or are they cutting corners?  I have seen a few
old player pianos that have pliable rubber cloth pneumatics that still
play after eighty years.  Today some people claim you should probably
plan to re-do pneumatics in ten years.  I tell my customers that I use
the best material that money can buy.  But is it?  Do suppliers like
Schaff really press the manufacturers for top quality?

I have had good and bad luck with Bilon.  My personal in-house pumper
player piano pneumatics were done with Bilon in 1973, and the player
still plays beautifully.  But another player on which I used Bilon for
the pneumatics (for a customer two states away in North Dakota) was
brought back less than a year later with a number of notes playing
poorly.  An examination of the pneumatic material showed some areas
full of pin-holes and leaking at the folds.  I held my remaining Bilon
stock up against a lighted window and discovered the same manufacturing
defect in various parts of the material.  I attempted to get a refund
from PPCo, but they said they no longer stocked it and sorry, no
adjustment possible.  So I would agree, there were good and bad runs of
Bilon.

If I still had a roll of Bilon on the shelf, I would not hesitate to 
use it but I would certainly hold it up to a window first to be sure it
does not have pin-hole leaks.  It was not as easy cutting the strips to
size, because it would not tear into strips like rubberized material
does.  And you definitely needed to use PVC-E glue to glue it on the
pneumatics.

So, I feel the same frustration as John Grant: there has to be
something out there better than modern rubberized cloth.

Larry Schuette
Raymond, Nebraska