Hi Dan,
I appreciate your input. I have done failure testing
prior to welding on my sub with exceptional success. I think that some of
the time flux core gets a bad rap because of the fact that the little buzz
boxes use flux core. Mine is a 350 amp mig computer controlled pulse welder
as speced by both lincoln tech specialists and my coach, an extremely
experienced and active pressure vessel welder.
I concure that one cannot be too
cautious.
I am interested in talking with you more at the
convention about this subject and appreciate your feedback.
Rest assured that I did considerable homework prior to
choosing the method that I am using now.
Thanks again & Best Regards,
Jim Kocourek
----- Original Message -----
Sent: Tuesday, July 24, 2007 7:50
PM
Subject: [PSUBS-MAILIST] Re: Mig
welding a sub
James
I believe it would be in your best interest to strive for
the highest possible weld integrity for the pressure hull of your
submarine. A weld procedure that is acceptable for a backhoe
bucket isn't necessarily adequate for Pressure Vessel Quality
work. Typical Quality Control standards for PVQ require
full penetration X-ray quality welds to acheive 100 % of the strength
required for such a demanding applicaton. While there are many welding
processes available to the average person, ( mig, tig, stick). Some are
better suited than others in a given situation depending on a
particular individuals skill and experience level. As an
example , I have seen "side bend" Mig weld tests performed by highly
skilled welders with ten's of thousands of hours of welding
experience split apart in the weld bead zone. Mig has a tendency to
exhibit very shallow penetration in certain circumstances. The trick
is to know WHA! ! T circumstances. If you are going to perform your own
welding I would recommend that you do what industry does. Take a weldor
qualification test in the weld process and welding procedure you intend to
implement in your build project. Get a copy of "The Procedure
Handbook of Arc Welding" by the Lincoln Electric Co. of Cleveland
Ohio. This an excellent reference book with a chapter devoted to
weldor qualification tests. If you have a hydraulic press in your
shop you can perform your own tests. If you plan to hire
someone to do the welding for you insist that they pass an approved
test administered by a qualified laboratory. Rework is expensive , do it
right the first time. And of course,......what is your life
worth?....... someone who says they can do it or someone who can
prove that they can do it.
Happy sub building,
Daniel Lance