John Farmer, Worcestershire, UK, is conducting a survey of thin
rubberized cloth sold by several retail firms.  He found some cloth
samples that had lots of pin-holes.

Using also the pressure test method described by Richard Vance at
http://www.mmdigest.com/Gallery/Tech/AeoW/rv_044.html in the article
"Testing the Bellows Cloth," he found some cloth samples that emitted
only a few slow bubbles while other samples created a mass of bubbles.
The pressure differential was 10 to 12 inches water gage.

John writes:

  "Following a complaint from a customer I have just light tested two
  lots of thin pneumatic cloth, from very different sources.  Both
  showed pin-holes, one sample very few, the other a lot.  Since I
  realise this could be a sensitive subject to fully address through
  MMD, could I ask that MMDers holding stock of any thin cloth, from
  any source, check theirs and let me know the results, and where their
  cloth came from."

  "I would also appreciate any comments about whether this is actually
  a problem, since I am just assuming that good cloth shouldn't show
  pin-holes when held up to a bright light?"

Please reply directly to  John Farmer <john@musicanic.com.geentroep>
[delete ".geentroep to reply]

Robbie Rhodes
Mechanical Music Digest