Marcel Michaud

["Gary R. Boucher" <protek@shreve.net>]

Marcel Michaud,
    I tried to return your note but my server would not take your address.
 I assume you are still on the mailing list here.  This is what I wrote:

Well, my design was not a good one.  But by accident I discovered a good
approach.  I actually machined a hatch "ring" that attaches to the subs
structure.  In this ring I cut a circular grove about 3/8 inch deep and at
the bottom center cut an O-ring grove.  I was going to place a 1/4 inch
O-ring in this grove.  However the O-ring would not stay put so I just
siliconed the grove full of RTV and placed a flat rubber seal of 1/8
thickness where the hatch mates to the ring.  The first idea was probably
the best with the 1/4 inch O-ring.  But I really never tried it.  I had
designed the outer flange of the hatch itself so as to be able to place a
square O-ring around it and get a secondary seal.  This is what I did and
it seals good.  I still have the flat material as my other secondary hatch
seal.  I have seen probably a better way to approach all of this.  A fellow
I know in Texas built a sub and he just used material that was about 1/2
inch where the hatch mates to the sub.  He turned an O-ring grove in the
hatch part and it seals fine.  The O-Ring does not fall out of the hatch. 
Perhaps it is from tension or perhapse from some RTV.  Don't know.  But my
system is too complicated.  There are better ways.  O-Rings are good.  They
are used in hydraulics for thousands of pounds of pressure.  I think if I
make another sub in the future I will just seat me an O-ring and be
comfortable with that.

Gary

----------
From: Marcel Michaud <mmichaud@shaw.wace.ca>
To: protek@shreve.net
Subject: Hatch Seal Design
Date: Monday, June 22, 1998 10:40 PM

Hi Gary 
            It's me Marcel, I have been working just about every weekend
for about a year now and I am ready for the machining of my hatch (seal
section). In Frank Busby's book Manned Submersibles  it show a hatch seal
surface where both face are  machined to maybe 45 deg.I dont know how a
neopreen or wath ever type of seal would stay in place with this kind of
design , I dont know if you have a copy of this book, I hade to look long
and hard to get it, very good book but not much on hatch seal design,
anyway I was thinking of your sub The Vindicator and the type of seal and
detail you used to keep the water out. Would you share your ideas on this
and the way you designed your seal and machine surface.
Thank's 
Marcel