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Re: [PSUBS-MAILIST] In my search for a simple, cheap pressure hull ...



Hi Michael

As far as I know, ABS and the U.S. Coast Guard will not yet certify
for human occupancy  for hire, any submersible vehicle made from anything
other than steel, aluminum, titanium or acrylic.

 Their main objection is not with the materials but with the critical fabrication
of the composite to reliably avoid entrapped air and to ensure the composite's
optimum fiber to plastic ratio for maximum strength.

 Graham Hawks' "Deep Flight" is made of E glass and so is Rob Innes' VASH,
"Sweet Virgin Angel". I used carbon fiber, Kevlar, Spectra and S glass in epoxy
for my first VASH, "Noland Won", like the first time aircraft builder I wanted to
be sure it was really strong enough for the abuse I had planned for it.

 For personal "experimental" subs it's a build at use at your own risk.
How great that risk is when it comes to composite submersibles has yet to be
fully determined. Although I've never seen the risk to be any higher than any
other metal and acrylic sub, when designed and constructed properly.
Again Jerry Stachiw would be the authority on materials for pressure vessels

Doc
 

"Michael B. Holt" wrote:

I went to talk with Dermott, who lives three doors away.  Dermott is
assembling parts for a helicopter, and we trade notes on the problems
of high-end scavenging for expensive bits of metal.

I asked him if he could fabricate for me frames of aluminum (his
favorite metal for obvious reasons).  I explained that I wanted
to build a faceted plywood hull (like Captain Nemo's Nautilus),
and then render it circular by plastering it with fiberglass.

Dermott suggested I build the frames out of aluminum, link them
with "C-channel" riveted or welded to the frames, and then cover
the whole with metal mesh.  Over the metal mesh would go the
fiberglass.

He warned me that using it might require the use of breathing
gear because of the fumes from the chemicals.

I think I remember reading about glass-over-metal mesh as a hull
material.  I know a small German sub from the 1960s was almost
like that.  But does anyone else recall a boat more recently
made like this?  Maybe I'm remembering a buoy or something ....

Mike