Re: [PSUBS-MAILIST] Syntactic Foam used to give extra strength to a pressure hull

Yes some syntactic foams have good noise canceling and sonar canceling properties that could make the Navy and/or Coast Guard take interest in your sub. But who knows what advanced gear they have now that could easily detect you in some other manor. Besides I'll likely be covering my syntactic foam with fiberglass or carbon fiber so with that as an outer surface they would get a good strong sonar signal off of it. That is of cause if the Navy ever turns on there sonar in the first place to see what's out in front of them. In the past they liked to play bumper boats with other subs and a hill here and there. :)'

I always suspected that if I made my sub(s) to good that a drug runner would steal it from me and perhaps even kidnap me to run it. But I try not to think about it to much. Paranoia is not going to stop me. I've been under taking the task of reading the whole PSUB list archive and it's packed full of wondrous things. I got more Internet Explorer pages and taps open then my PC can handle. One I recently came across, that I think we should be reminded of is this little quote.
"Sub builders have enough technical problems to deal with without
Family, friends, neighbors and the "well meaning" often providing
Unsolicited comments and judgements.

Here then is, IMHO, the appropriate response (and I paraphrase . . .)

"Far better it is to dare mighty things,
To win glorious triumphs, even though checkered by failure,
Than to rank with those poor spirits who neither enjoy much
Nor suffer much, because they live in the gray twilight
That knows neither Victory nor Defeat."

Put it up on your shop wall behind your visitor's chair. " end of quote

Cheers
Brent H

From: "George Slaterpryce" <gslaterp@hotmail.com>
Reply-To: personal_submersibles@psubs.org
To: <personal_submersibles@psubs.org>
Subject: Re: [PSUBS-MAILIST] Syntactic Foam used to give extra strength to a pressure hull
Date: Fri, 19 Jan 2007 08:30:11 -0500

I think this is interesting, it would really help with the cost of building a sub too if one could do it with fiberglass.

Problem is... I dunno if you wouldn't get hauled off to jail for making a quite PSub, this method of building has a large potential to really get the attention of some government beaurocrat on a power trip. Still... very promising building technique.

----- Original Message -----

From: Brent Hartwig

To: personal_submersibles@psubs.org

Sent: Thursday, January 18, 2007 5:54 PM

Subject: [PSUBS-MAILIST] Syntactic Foam used to give extra strength to a pressure hull

I just found this data on some externally-applied hydrostatic pressure test done on fiberglass filament wound cylinders covered in syntactic foam. What if you covered a steel,or other type pressure hull of a sub in a even layer of syntactic foam?? If you hit something with your sub it would also give some protection to the interior pressure hull. Also it would insulate your sub from hot and cold temperatures as well as from noise. You would also have a none flood-able buoyancy safety factor.

http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0605963

"Title : SYNTACTIC-FOAM, FILAMENT-WOUND COMPOSITE PRESSURE HULLS.

Descriptive Note : Final rept.,

Corporate Author : GM DEFENSE RESEARCH LABS SANTA BARBARA CALIF

Personal Author(s) : Robertson,R. M.

Report Date : SEP 1964

Pagination or Media Count : 73

Abstract : External hydrostatic pressure tests were conducted on 12 fiberglass filament-wound cylinders, each 12 in. Long with an ID of 5 in. Six of these had a wall thickness of 0.210 in., designed to fail by buckling at 2000 psi; the other six had a wall thickness of 0.305 in., designed to fail by buckling at 5000 psi. Three of each type were covered with an external coating of INLYTE (a buoyant syntactic foam previously developed by the contractor in an effort to stabilize the G. R. P. Against buckling. The syntactic foam density was 44 lb/cu. Ft. The six uncoated cylinders were used as controls. Long cylinders of fiberglass exhibit collapse characteristics under external hydrostatic pressures. The compressive stresses are not developed to their full potential. The tests were conducted to determine if a coating of syntactic foam would stabilize the units to allow more efficient use of the compressive stress. Conclusions: By coating cylinders with a layer of low-density syntactic foam, such as INLYTE, the unit is stabilized in the buckling mode, and a great increase in strength is achieved before rupture from externally-applied hydrostatic pressure. Also, the buoyancy of the composite structure is significantly increased. (Author)"

Regards Brent

From:  Ian Roxborough <irox@ix.netcom.com>
Reply-To:  personal_submersibles@psubs.org
To:  personal_submersibles@psubs.org
Subject:  Re: [PSUBS-MAILIST] Concrete submarine
Date:  Thu, 18 Jan 2007 10:04:48 -0800
>
>Yeah the website is new (to me anyway).  I think this guy was
>posting to the psubs mailing list a couple of years back (and
>also shared some pictures then).  But the website has better
>pictures.  Hope we gave him a better welcome than he's getting on
>rec.boats.building, one reply accusing him of faking the
>pictures.... moron...
>
>Ian.
>
>On Thu, 18 Jan 2007 10:35:34 -0500
>Michael Holt <mholt@ohiohills.com> wrote:
>
> > I think we've seen this before, but I don't recall having access to a
> > website.  A note was placed here:
> >
> > http://groups.google.com/group/rec.boats.building/browse_thread/thread/4d063f6278116dfb?hl=en
> >
> > It led to this website:
> >
> > http://www.tolimared.com/submarine
> >
> >
> > M
> >
> > --
> > It's amazing, really, how much people think you must know if you know about something nobody else much cares about.  -Tommy Whittaker
> >
> >
> >
> >
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