A big part of welding a submarine together is the fit of all the parts before the welding begins..Welding the boat together is in some respects the easy part...the hard work has already been done..a good welder will know if he or she has done a good job and if it is welded with the TIG method,,, then all the welds will be very good if the person knows what they are doing. If some one is thinking about buying this sub on E Bay and is concerned with the safety of the welds,, then it would be simple to grind out the welds and have a pro re weld the boat. It would take me about a week to grind out all the welds and re weld the boat. This would eliminate any concerns...
Any one interested in this can e mail me. Dave from Advanced Welding in Marathon Florida
Ian Roxborough <irox@ix.netcom.com> wrote:
Welcome Dave. Thanks for sharing some of your NDT experience, feel
free to go a longer if you like.
A while back I started collecting NDT testing components with the
intent of being able to do my own ultra-sound testing. I've just
been buying things that I could afford (i.e. when they where cheap).
I've been wondering about the cables used for connecting the tranducers
to the signal generator and O-scope. Is there anything special about
these cables? Could I make them myself? Cables and an Oscope are
the only bits I've left to collect before I can start practicing.
I have a friend who has worked on Ultra-sound NDT robots (the type
that inspect pipelines, etc.), he's able to give some pointers
and keep in the right directions (gives me hints on what to buy).
What are your thoughts on the DIY ultra-sound NDT? I figure even
if I suck
at it, the worse that can happen is I redo a weld that
was good. Given that most ksubs/psubs are lowered to X feet deeper
than operating depth for a certain length of time as the main form
of materials testing, I don't think I'm introducing any additional
danger by attempting my own NDT).
Anyway, a big WELCOME ABOARD, great first post!
Thanks,
Ian.
On Thu, 25 Nov 2004 08:06:22 -0800 (PST)
David Hahn wrote:
> Hi,
> First post from a newbie, but thought I might comment
> on the welding issues. I work at a powerplant, have
> some NDT certs (mag and PT), and am a CWI, as well as
> a boiler inspector, so have gotten to be a little
> familiar with some of these issues.
>
> I am not sure where you are, or if there are any NDT
> companies near you but if you can find a good
> ultrasound man you can find out a lot more about your
> welds then you can with
xray. X-rays will show slag
> and porosity pretty well, and if you have a crack or
> delamination that runs the same direction as the beam
> it shows up pretty well, but we have had trouble with
> cracks that are 90 degs to the beam. A lot of both
> the UT (shearwave) and X-ray are in the
> interpetation, so the operator is really important.
>
> Actually, you could probably find out a lot about the
> welds if you had just a simple ultrasound d-meter.
> These are just depth meters and catch a sound bounce
> off of the back wall of the weld or piece of steel.
> Really uneven readings would indicate slag.
>
> But that would be sort of a half measure. In an
> industrial settting we would sandblast all the welds -
> interiour and exterior. A visual inspection would
> tell you if they back gouged the welds and made a good
> full penetration weld, or of they just gooped it
over
> and (horrors) puttied it to make is smooth. A dye
> penetrant test would reveal pits, porosity, cracks
> etc, and a dye penetrant setup is cheap to buy and
> pretty much fool proof. It won't tell you what is
> inside a weld, but when you are talking about 1/4" to
> 3/8" thicknesses you can see most of the problems
> looking from either side. Pressure vessel
> manufacturing code would require x-rays on the
> longitudinal welds as well as the cirumferential
> welds. Some of that is probably for insurance
> purposes, and some for thicker-walled vessels.
>
> Sorry, I didn't mean to run on so long, and maybe
> everyone already is familiar with welding and NDE -
> don't mean to be a know-it-all (because I am a real
> newbie when pressure comes from the outside) but if I
> was going to climb into a sub that someone else had
> welded and I didn't know anything about it, I
would
> sandblast it and run a dye penetrant test on all
> welds, inside and out. Bad spots would get ground
> out, retested to make sure that the defect was gone
> and carefully rewelded. These would be the minimum
> steps that I would take to ensure that the welding was
> done right, and that it wasn't likely to unzip.
>
> Best of luck,
>
> Dave
>
>
> --- "Dan H." wrote:
>
> > Ian,
> > I hate to put a damper on your enthusiasm but!
> > I looked at the larger pic you sent and first off
> > the view ports don't look
> > right.
> >
> > The sub looks like a take off of a K design all
> > right but the builder took
> > many liberties. After reading Gene's look-see and
> > what I see in the larger
> > pic, you may not want it unless your only diving in
> > the
shallows. The
> > trailer and tire issue you can deal with but not
> > being sure of the weld is a
> > bigger matter. You can have it X-rayed and repair
> > if needed but that's not
> > cheep.
> >
> > The bigger problem is with the view ports. From
> > what I see in the pic,
> > there isn't enough steel in the viewport housings.
> > They are thin and don't
> > have nearly enough surface to back up the lenses.
> > They look to be about a
> > eight inch lens size and need about an inch and a
> > half of back up all they
> > around the interior side of the lens. The hole on
> > the interior side of the
> > housing should be about six inches. You'd have to
> > change all of them to
> > ever take it to 250 feet.
> >
> > If you get it cheep enough, it may be good buy for
> > materials but
already to
> > high priced for what you'd be getting.
> >
> > Sorrrry, Dan H.
> > ----- Original Message -----
> > From: "irox"
> > To:
> > Sent: Wednesday, November 24, 2004 6:02 PM
> > Subject: Re: [PSUBS-MAILIST] Two man sub on ebay (or
> > buying used submarines)
> >
> >
> > >
> > > Dan, thanks for the tips.
> > >
> > > Here is a bigger picture:
> > >
> >
> http://www.watercraft.gs/uploads/adphotos/a30p1553012798orig.jpg
> > >
> > > It seems to have a built in trailer, which while
> > interesting, isn't
> > something I'm
> > > really keen on. Atleast not on the implementation
> > in the picture. But it
> > does
> > > look like it could be easily removed with bolts.
> > Should I buy it I might
> > consider
> > > putting K350 style battery pods using the bolt
> > holes from the tailer bits.
> > >
> > > I'll pay close attention to the welds. The
> > welder/NDT talk from the first
> > > Psubs convention is coming back to me now (I'll
> > review the notes from
> > > that talk before I view the sub).
> > >
> > > The end-cap thickness tip is a good one. I might
> > beable to measure the
> > > thinkness through the main (down pointing) view
> > port (assuming it has
> > > one).
> > >
> > > From the picture is appears that the builder was
> > not planning on putting
> > > in a rear thruster (something I might change -
> > since I'm not planning on
> > > side thrusters).
> > >
> > > I'm not too
keen on the MBTs either, but it's a
> > clever idea. According to
> > > the guys I talked with today, it's got plumming
> > and gauges inside, but
> > > they don't really know much about submarines.
> > >
> > > Thanks,
> > > Ian.
> > >
> > > -----Original Message-----
> > > From: "Dan H."
> > > Sent: Nov 24, 2004 2:46 PM
> > > To: personal_submersibles@psubs.org
> > > Subject: Re: [PSUBS-MAILIST] Two man sub on ebay
> > (or buying used
> > submarines)
> > >
> > > Ian,
> > >
> > > It sure looks strange with the tires hanging off
> > of it but It's an idea.
> > > The pic is so small that it's difficult to see
> > much. One thing for sure,
> > it
> > > doesn't look much like the Lake Diver pic
they're
> > using to sell it with.
> > > I'd say it's just about fraudulent to sell it with
> > that pic.
> > >
> > > Since there isn't any external battery pods I'd
> > say it's a deviation of a
> > > K-250 not K-350. I can't see if there's a rear
> > thruster. K-350 has a rear
> > > thruster. The hull ends are 3/8 thick on a K-350
> > and only 1/4 thick on a
> > > K-250 but you won't be able to measure it with out
> > drilling a hole.
> > >
> > > Since it's never seen water, rust shouldn't be an
> > issue. Just take a good
> > > look at the welds. Visual inspection isn't all
> > there is to it, but if
> > they
> > > look good, at least they might be good to the
> > root. Just look at the
> > > overall workmanship. If the builder spent the
> > time and
made what you see
> > > look good, what you can't see is more likely to be
> > good as well.
> > >
> > > Is it plumbed for air and tank vents and wired for
> > power including fuses,
> > > lights and thru hulls? The e-bay add implies it
> > is. But they don't seem
> > to
> > > know much.
> > >
> > > If it's only a painted hull, it's about half done.
> > >
> > > Good luck, Dan H.
> > >
> > > ----- Original Message -----
> > > From: "irox"
> > > To:
> > > Sent: Wednesday, November 24, 2004 2:35 PM
> > > Subject: [PSUBS-MAILIST] Two man sub on ebay (or
> > buying used submarines)
> > >
> > >
> > > >
> > > > Hi,
> > > >
> > > >
from talking with one of the current owners, I
> > think that it's this
> > > > submarine here:
> > > >
> >
> http://www.watercraft.gs/listing.php?main=Submersibles
> > > >
> > > > Unfortunately, the people who are selling it
> > didn't build it and don't
> > > know
> > > > anything about it. So I've been unable to ask
> > questions about the
> > origin
> > > > of the steel, fittings, pipes, qualitiy of the
> > welds, etc... They are
> > not
> > > sure
> > > > if it's a K350 or a K250 that's been modified.
> > Built in trailer,
> > > interesting,
> > > > but I'm not sure it'll stay that way if I own
> > it. It does appear to
> > have
> > > > internal battery box, everything else I know
> > > >
>
> > > I'm going to try and see it as soon as possible.
> > > >
> > > > I think with subs getting more popullar we'll
> > need to write a guide
> > > > to buying used submarines.. ;-)
> > > >
> > > > Any tips (K250 vs K350 type differences,
> > mistakes to look for, etc.)
> > will
> > > > be most welcome.
> > > >
> > > > Thanks,
> > > > Ian.
> > > >
> > > >
> > > >
> > > >
> >
> ************************************************************************
> > > >
> >
> ************************************************************************
> > > >
> >
> ************************************************************************
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complies
> > with
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