John,
it would be a great honor for me to try to respectfully answer - at least partially - your topic.
But please can you give a little more technical information (materials, range of thickness, welding process...) of what exactly you are interested in?
You may forgive me - and I hope all other colleagues may agree - but the issue is a little tricky and thus not as easy to explain.
Thank you in advance and regards,
Stephan