Welding was: [PSUBS-MAILIST] CSX-1 technical inquiry.

[MerlinSub@t-online.de (Carsten Standfuß)]

Captain Nemo schrieb:
> 
> Hi Carsten!
> 
> Just wanted to explore the technical side of sub-building for a while.
> 
> When I asked what kind of "joint" you were using: this is a structural term
> describing the way the steel plates are positioned next to each other before
> welding; has a lot to do with the final strength of the finished product.
> 
> For example, when two plates are simply set side-be-side, touching on the
> edges, and then welded, we call that a "butt joint" because the two plates
> "abut" each other.  If the edges to be joined are beveled slightly with a
> grinder, this gives deeper penetration for the weld, and is sometimes called
> a "beveled butt joint."  When the plates are slightly overlapped and then
> welded, this is called a "lap join", and so forth.  I was just wondering
> what kind of joint you were using.
> 

Okay - I did it this way : One side of both plates deep V grinded.
Plate to plate tack welded with a distance gap of 0,5 - 1 mm. 
Than weld the deep V grinded side first. 
Go to the other side (if possible) and grind the weld gap out up to the 
time the weld gap is pure clear silver facing iron . Weld this side.
If everything is correct and the structure for example will be destroyed
- 
the crack should be in the metal of the plate and not in the welding
area. 

If I weld with a MIG welder there is a great possibility that the first
1 inch is to cold and also the last 1 inch. Special if you start 
the day with this structure - and the scruture is strong and cold. 
For this reason I grind this 1 inch out if I want to length the weld -
and also if the weld was cold down during a breakfirst break.  

The multi layer welding on the regulator tanks has much more layers than 
nessesary for the reason that I am a non-licence welder - and wanted 
some more security in this item.. 

In general - If I do not know how to weld a special item - I ask a
proffesional
from the company which sold me the welder , the gas and the wire.  

In general I prefer the Mig process - is fast and easy. But somethimes I
use
the stick welder - for examle if the space is to limited for the
MIG-hand-gun. 
But be careful with the MIG process - ask a teacher ! 
The metal has to be cleaned from everthing - grinding to the pure rust
free metal. 
With a stick welder it is not so important because in this process the
dirt comes 
high and goes in the glas-surface-garbage layer.. (may you have a
shorter word..). 
In the Mig process it goes into the weld..  
In general ask a teacher - some of my first stick welds during the
shipbuilding
study and before Sgt.Peppers looks very good on the surface - we break
them for 
test purpose and there were dirt near the base.

Welding is a three kind process : 
1.) Teaching by a profesional 
2.) Training 
3.) see point two. 

I thing the finest and best welding can be done with the WIG process -
but 
I don't use it - may you should ask John & Monica - seems they use this
process. 

> If I understand your description of the welding process you're using, it
> sounds very strong.  I'm visualizing a butt-joint with one bead over the
> seam; two more beads (one on either side of the first pass); two more beads
> riding the crease between beads 1, 2, and 3; and a final "cap bead" pass
> made down the center again.  If we cut a slice out of it perpendicularly,
> and looked at the weld beads from the end, it would look something like a
> diamond shape.  To me this sounds very strong.
> 
> I just came up from the shop and am taking a break.  Just welded in a
> bulkhead for a small hatch which will allow me to access the end of the
> tailcone for maintenance of the control shaft packing glands.  Also
> installed a big coupler which will increase the emergency escape lockout
> flood valve diameter by 325%, so I'll be able to get out faster if I get
> into trouble.  Installing the watertight coupler for the underwater
> telephone transducer next; then it's weld in the supplemental systems
> battery box, and after that the hard stuff is done.  Time to vacuum out the
> pressure hull, paint the inside, start putting her back together, and finish
> up the exterior detailing.  Then, it's time to go diving!

This year ? 

see you - Cssxarsten 

> 
> Pat
> 
> ----- Original Message -----
> From: "Carsten Standfuß" <MerlinSub@t-online.de>
> To: <personal_submersibles@psubs.org>
> Sent: Thursday, June 21, 2001 9:10 PM
> Subject: Re: [PSUBS-MAILIST] CSX-1 technical inquiry.
> 
> > Hi Pat..
> >
> > > Captain Nemo schrieb:
> > >
> > > Carsten,
> > >
> > > In welding your pressure hull together:
> > >
> > > (1) What kind of joint are you using between mated plates?
> >
> > My translation book is not very helpful with "mated plates".
> > But in general I use O-rings for pressure parts and flat rubber
> > gasket for non pressure parts. The main Machinery hull joint
> > will be a mixture between a o-ring, a hard rubber flat gasket
> > just a little smaller in tickness than the O-ring
> > and on the outside a fluid rubber sealer to prevend rust.
> >
> > >
> > > (2) Are you welding in single or multiple passes?
> >
> > In a single passes if ever possible on multi-layer weldings.
> > The regulator tank joint flanges has 6 layer weldings.
> > I pre-heated the steel with a gas flame and make all layers during
> > the time the material was hot from the welding process.
> > It is clear vissible that the last layers on the hot material
> > gets much better than on the cold material.
> > Sometimes I work overnight - because of something went wrong and I
> > lost time by repair work (grinding) on the weld etc.
> > Single layer welds I did on different days - but I grind the first
> > 1-2 inch were the old weld starts or end - specialy if I use the Mig
> > welder - this parts can be to "cold" with a bad conection.
> >
> > >
> > > Pat
> >