Bruce Clark, in 000304 MMD, wrote that samples of different 1920s
pneumatic cloth varied from like new to useless when examined several
decades later.  He and others write that different batches of pneumatic
cloth available today seems just as variable:  some cloth deteriorates
rapidly and others remain like new.  Bruce asked where one can buy
pneumatic cloth that is guaranteed.

A wholesaler or supplier needs assurance of consistent quality before
a guarantee can be offered.  What manufacturing process controls and
material specifications and product tests could apply?  What tests
could the supplier and the customer perform to determine the quality
and composition of the material?

How does the cloth industry specify quality of fabric for sails and
airplane wings?  Are there standard specifications and test procedures
for natural and synthetic rubber sheet?

Craig Brougher wrote to me:

  "Natural gum rubber deteriorates quickly unless stabilized, too;
  it gets hard.  But different recipes age differently: the fillers
  determine the durometer and partly the aging characteristics.
  Fillers are usually clays.  Duo-Art used some kind of grey filler,
  and others used brown fillers.  Then there were the white rubber
  layers.  Perhaps somebody can inform us all about this."

It sure appears that the player piano industry, then and now, suffers
from pig-in-the-poke quality of pneumatic materials.  As a result,
with each job he begins the player piano rebuilder risks an unhappy
customer and a ruined reputation.

Robbie Rhodes