Hi Randy,  This is my opinion on the best type of material to use
for Duo-Art Accordion Pneumatics.

I have used tan pneumatic leather since I first started rebuilding some
twenty-five years ago.  I've kept a close eye on my work over the years
and am happy to report that none of the accordion pneumatics I've
rebuilt have ever failed.  None of them have yet to require
re-rebuilding.

Conversely, I've seen a number of units that were recovered with
high-quality pneumatic cloth and every single one of them needed
recovering when I came in contact with them.

The real problems with pneumatic cloth are at least two-fold.  First,
as you correctly stated, it's not flexible enough for the job.  If the
makers of the Duo-Art mechanism had thought for an instant that
pneumatic cloth would have been able to do the job as well or better
than tan pneumatic skin, they would have used it and saved lots of
money.

Second, and perhaps more importantly, pneumatic cloth is, in my
opinion, much harder to seal where the two pieces join without getting
stiff.  Although I've never done any comprehensive testing, it seems
to me that the glue penetrates the cotton fibers and they become very
stiff.  With the leather, it does seem to penetrate to a degree but it
doesn't seem to get stiff.

Lastly, it's my opinion that to achieve original quality, you must
use materials that are at least as good as the original.  In other
words.... duplicate the original.

Musically,

John A. Tuttle (john@player-care.com)
Player-Care (www.player-care.com)