Re: [PSUBS-MAILIST] Carbon Fiber

[TeslaTony@aol.com]

In a message dated 8/14/00 12:06:41 AM Pacific Daylight Time, 
vulcania@interpac.net writes:

>  "Actually I think that lighter _is_ better since I want to have one or more
>  drop weights, and it's nice to be able to lose as much weight as possible 
if
>  you have to surface fast."
>  
>  Well yeah, I can see your point; and I suppose there are pros and cons to
>  just about everything.  Having the extra hard ballast in the form of a drop
>  weight will definitely give you a lot of positive buoyancy when it's time 
to
>  go.  And I've thought about this, too.  A few of the problems I encountered
>  were: the size and shape of the extra ballast: making a releasable
>  attachment between the ballast and the hull; the potential for structural
>  failure between the steel weights and the composite / frame hull structure;
>  etc.  To me, it just seemed more convenient to have weight and buoyancy
>  self-compensate by using a hull material that compensated displacement
>  weight requirements integrally, while minimizing the need for add-on
>  components.  But there are two sides to every coin.  Done right, composites
>  with releasable ballast could have some advantages. Like Suds said, the
>  stuff is easier to form complex shapes with; and to that I'd add "it 
doesn't
>  rust, either".

I was planning on using the dropweights as skids so that I could sit the sub 
right on the floor of the garage or ocean, and if there are wheels attached I 
could just dump the sub on the ground and let it slide into the water instead 
of getting the trailer all wet.
 I like no rust.....

>  Well, Tony, I don't know what it might cost to rent a pressurized 
autoclave;
>  but the one I saw (and I think it was in a program about the construction 
of
>  DEEP FLIGHT) was a walk-in chamber.  I don't know if one big enough to cure
>  something the size of hull components would be economical to rent; but then
>  again, somebody might be able to find an economical way to go on this 
point.
>  (Maybe some company that  has one would rent you time in it, for example.)

Renting time is what I had in mind, especially considering that the only 
place I could put the thing is the back yard, and there is no way to get 
stuff in or out that is that big.

>  But most general metal fabrication (a lot of what it takes to build a sub)
>  can be done very reasonably in a home shop with a welder, torch, and some
>  forming tools and grinders.  Shaped plates can be professionally
>  manufactured and then weld-assembled by the home craftsman.  Agreed: it
>  costs megabucks to acquire the tooling necessary to produce a steel 
teardrop
>  hull; one made out of composites could be less expensive.

I have few tools, and I have little use for a welder except for making the 
sub, a one time project.

>  But then again, why do we need an eliptical hull?  For hydrodynamic
>  efficiency?

That's the general idea, although the other side is that I haven't seen 
anyone with that type of hull before.

>  A nice compromise might be to make a more conventionally-shaped
>  steel pressure hull (say, a cylinder with hemispherical endcaps) and 
enclose
>  that in a composite shell of the desired shape.  This way, the p-hull would
>  be strong, easily made, and (if it matters) certifiable; and the outer hull
>  could be easily produced because it could be free-flooding and wouldn't 
need
>  to withstand depth pressure.  One might even conceal integral ballast tanks
>  in the void between the p-hull and outer shell.  Done that way, one could
>  probably avoid expensive composites and the autoclave, and lay-up a 
suitable
>  teardrop shell of regular fiberglass built upon a basic metal frame that
>  bolts to the p-hull.

I was thinking about that, and it does seem like a pretty good idea. The only 
drawback would be the amount of kinetic energy that gets built up with all 
that water, but that can be negated by pressurizing the secondary hull with 
some inert gas like Argon (oooooohh.....make the secondary hull clear and 
stick a Tesla Coil in it while the hull is filled with Argon, it would make 
some real neat lightning bolts).

>  Yeah, supply can be a problem, and one definitely needs to shop around.
>  Back in Cal where I built the Nautilus, a place called ALCO sold all kinds
>  of metals.  At first they didn't want to deal with me; but when I showed
>  them pictures of what I was building, they got behind me and gave me good
>  deals on materials.  (Let me walk the yard and pick whatever I wanted from
>  the bins and racks.)  And,  an absolutely wonderful gent by the name of Joe
>  Garske let me roam his boatyard, and sold me stuff at next-to-nothing
>  prices.

Cal? As if in California? I live 45 minutes from San Fransisco! You may have 
just solved my supply problem!

>  Now, Joe was one of those tough-as-leather guys who operates a crane-barge
>  company, and was building steel ships since WW-II.  When I first came to 
his
>  boatyard,  he called me a "playboy" and was running me out of the place
>  until I showed him I knew how to compute the weight of metals and the
>  displacement of oddly-shaped vessels.  Only then did he start to take me
>  seriously, and agree to sell to me.  As my project progressed, he'd come
>  over and see it from time to time; and his willingness to support me
>  increased when he realized I was actually making progress.  So, I know
>  getting acceptance can be hard.



>  Submarines are unusual projects; and guys in the business of working with
>  steel are probably going to look at the neophyte sub-builder like he's some
>  kind of wingnut or something.  That's to be expected.  But I was able to
>  convince people with "the means" to help me, and they eventually took an
>  interest in my work and gave me more-than-reasonable prices.

A sub is an unusual project? Someone might think I'm nuts? Hmmmm.......this 
is odd....I thought EVERYONE built subs!

>  To anyone wanting to build a sub, and needing the help of people with 
access
>  to stock and equipment, I say: be persistent.  Look 'em straight in the 
eye,
>  tell 'em who you are, and tell 'em what you want.  Expect them to roll 
their
>  eyes, laugh and cuss,  and spit on the ground; but don't give up.  Keep at
>  'em, and if you can convince them you're serious, you might be surprise at
>  how much help they may be willing to offer.  And if they still won't go for
>  it, don't give up.  Find someone else who will.  If you believe there's a
>  way, you just might find it.  That's how it went for me, anyway.  It wasn't
>  easy, but it wasn't impossible, either.

I'll keep you advice in mind, especially since I'm probably going to need it 
more than you think.

>  Hey, I got a horse that needs shoes!

I could shoe your horse, but I think you would be more satisfied with the job 
that I do on the sword that I sell you to cut off your horses head after it 
breaks a leg from stumbling because of a lousy shoeing job.

>  Yeah, I hear ya, man.  Why not give that idea I mentioned above (a steel
>  p-hull in a fiberglass shell) some thought?  Might be the easiest way to
>  have the best of both worlds, and produce a boat that will do what you're
>  looking for at the minimum expense of time, effort, and money.

There is a company that sells propane a short bike ride from my house, and 
they have a yard full of every type of propane tank imaginable, and if they 
sell tanks as well I guess I might as well go the direction you suggested.

>  Anyway, that's about the best suggestion this "backyard bandito" can offer.
>  Whichever method you decide to use, I wish you good luck with your project.
>  
>  VBR,
>  
>  Pat
>  
Thanks for the help, and I'm going to need as much luck as I can get my hands 
on.

Thanks,
Anthony