[PSUBS-MAILIST] Re: Mig welding a sub

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 WHAT 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.