Mike Kitner mentioned that he would like to measure the leakage
through various woods, like red gum, to see the difference between
them. Well, Mike, you have provided help to a lot of people over the
years and I welcome the opportunity to return the favor.
Several years ago, my friend Phil Dayson demonstrated just such a
device at the annual MBSI meeting in Seattle. As a direct result
of his efforts, I was able to design and build a similar device which
I used to measure the leakage of a set of pneumatics that I needed to
restore. Phil's device uses liquid manometers and mine uses Magnehelic
pressure differential gauges. I demonstrated my version at the last
MBSI meeting in Philadelphia.
Phil's description is in the MMD Archives and, if you'd care to contact
me, I would be glad to describe how I made my device. With it, I was
able to confirm that the method I used to seal the pneumatics reduced
the leakage from as much as 100 cubic inches per minute to as low as
3 cubic inches per minute. I was able to see the difference made by
sealing one tiny pinhole.
[ See Phil Dayson's articles indexed at
[ http://mmd.foxtail.com/Archives/Authors/Aut783.html -- Robbie