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Re: [PSUBS-MAILIST] MIG Welding a Sub



Jay, Asherah was between STAR I & STAR II. The star designation was (for the newbies) an in-house acronym for Submersible, Test and Research. Asherah, on the other hand, was a commercial job for Dr. George Bass at the University of Pennsylvania for work out of Bodrum, Turkey and Yassi Ada (the primary dive site at the time) and was not tagged with a star number. She was built in three months flat, from the first phone call to launch, and cost $25,000, including tax, tags and dealer prep. I loved that submarine, tried hard to buy it off the dentist who had it first after Bass, couldn't do it. STAR I, built by three engineers at home (mostly) was the first modern psub in my view, as it was built at home, and was a resounding success, all things considered. It was dirt simple, compact, light weight, safe and more or less bulletproof. It was used as a General Dynamics test bed for compensated batteries, and even ran a fuel cell, briefly, plus did some minor contracts, and was, of course, the first in a series. Pretty cool for the day, or any day, come to think of it. Vance


-----Original Message-----
From: Jay K. Jeffries <bottomgun@mindspring.com>
To: personal_submersibles@psubs.org
Sent: Tue, 31 Jul 2007 8:31 pm
Subject: RE: [PSUBS-MAILIST] MIG Welding a Sub

Sorry for the late reply.  You need to be careful with syntactic foam.  The old Asherah (STAR I) had its main battery foamed in with syntactic foam which resulted in a major stumbling block for refurbishment as it was very difficult to remove.  This submersible and a custom built saucer submersible were stored in a warehouse next to where we docked in Boston.  Took forever to rebuild Asherah due to the syntactic foam and the saucer had major stability and power issues.
R/Jay
 
 
Respectfully,
Jay K. Jeffries
Andros Is., Bahamas
 
A skimmer afloat is but a submarine, so poorly built it will not plunge.
 
From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent Hartwig
Sent: Thursday, July 26, 2007 11:16 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] MIG Welding a Sub
 
Hello Frank,
Did you say enthusiasm? Be careful what you wish for. ; )'
I've never seen a sub that didn't have continuous welds on the parts of the stiffeners that contact the outer skin. Do you know of any I can look at. Not to say that your method isn't good, I just hadn't heard of it before. I would think it would be a rust nightmare if done on a steel hull. Unless you back ground the part of the ring that was going up against the outer skin like you normally would to weld it, and then after stitch welding it, sand blasted it, epoxy primer it, paint and then fill the groove with a product like Sika Flex 292 and then Rhino coated the whole inside of the pressure hull.  I hate having to grind and/or sandblast paint over and over and over and over. There has to be a better way.
 That's not to say that all areas of a sub shouldn't be designed, so you can get to them for inspection and maintenance later, as you said.  That is one on my biggest things I spend time working up designs for. I've seen so many museum and PSUBs that were not designed this way, and it made working on them very hard if not impossible, without doing some very serious cutting.
The RV Needlefish, for all it's great innovations that I learn much from, had allot of areas you couldn't get to with out destroying the bow, stern, and saddle tanks, to do so. I'm under the impression that trying to bond fiberglass composite, over and onto a steel pressure hull wouldn't be a good bond. This being mostly because they expand and contract at different rates. I would like to hear from others with more actual experience with composites on this. I'll need to ask Karl Stanley about this as well, since Idabel has built with composites attached directly to the paint of the steel hull.
Will the steel hull of the R300 try to expand and contract, at a different rate then the syntactic foam around it, and in doing so, try to break it. Or will the syntactic foam so insulate and absorb heat and cold changes, that they work together?
I'm thinking about casting syntatic foam between the internal ribbing of this K-250 I'm working on, by way of infusion molding it. I will do this after I've installed T stock steel inbetween the support ribs horizontally, and after I've applied a Rhino type coating to deal with the expantion and contraction of the steel. The T stock will do basicly two things, give strength to the hull and keep the syntactic foam from falling out, since on the K boats the support rings only have under cut areas on one side, because they are made of rolled angle iron as most of you guys well know.
I think I would like to heat treat the whole completed pressure hull of my sub if I could, like Karl Stanley did on Idabel. I'm not sure how much it cost him, but I can find out.
http://stansub.fotki.com/the_submarine-1/the_submarine_under/heat_treatment.html
Regards,
Brent Harwig

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