Hi All, I would agree with Jim McFarland's rebuttal to my testing
procedure with the exception that the problems most often associated
with bad pneumatic cloth have generally been that the cloth was
defective from the factory, i.e., that the layer of air-tight material
was not uniform.
Naturally, if there are any pin holes in the cloth, this indicates
an area that is very thin, not just that there is just a hole in the
cloth. Ergo, those area around the pin hole are much thinner, and will
wear out more quickly. So, in essence, running a real-time test will
render the same basic results without the effort of making a bellow
and opening and closing it thousands of times. Furthermore, you
still have inescapable "other factors" which can influence the outcome
of the test.
Also, the clay content in cloth, which can be tested to a degree
with sunlight, is another real problem that also shows up in real-time
testing. However, it too requires the construction of a bellows
assembly of some sort, and at the risk of sounding redundant, involves
other factors which influence the final results. Naturally, one could
also test all of those other factors, and, finding them to be the same
as they were prior to the test, could arrive at the conclusion that the
cloth broke down prematurely. But why go to all that hassle.
My example of the pouch material was only given to prove, to some
extent, that real time testing can render results that are far from
accurate. And, in that regard, perhaps there is some merit to running
both tests. But, in my opinion, the cart has to come before the horse.
John A Tuttle
Brick, New Jersey, USA