[PSUBS-MAILIST] gasket test results

[Rick Patton via Personal_Submersibles]

Good luck on your upcoming test Hank. How are you launching your barge once
it gets there to the dive spot?
While on the subject of gaskets and 0 rings, I have some subcon and
blueglobe threw hulls. Sub Subcons of course have an O ring that sits in a
groove and is screwed into a threaded ss plug that is welded into the hull.
I have two concerns,1) how do I know when to stop tightening it as it won't
be able to compress with depth and 2) I would think that the O ring might
distort with the screwing motion as it snugs down. My preference would be
to drill out the ss threw hull plug so that the threaded shaft of the
Subcon would just pass threw and then put a backing nut on the inside to
compress it but then the hull plug would have to be in my mind too thin to
be able to get a nut on it. On the Blueglobes, how do you know when it is
snugged enough without doing any damage to the fitting?

Rick

On Wed, Jul 8, 2015 at 2:15 AM, hank pronk via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> I did my testing this morning and found some scary results.  I bonded EPDM
> gasket material to my port test chamber and tested a port to 500 psi.  The
> gasket extruded about 1/16 of an inch.  When I greased the surface of the
> gasket and pressured it to 500 psi, the gasket extruded 1/2 inch.  When the
> pressure is released the gasket returns to its original position.
> When the same test is done without bonding, I get the same result.
>
> My next test will be with the bearing surface machined to create tiny
> ridges for traction.
> Hank
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