Thanks for the vote of confidence, Bart! There are all sorts of approaches to welding, and every situation is somewhat unique. I did 2" to 6" stainless steel thinwall tubing welding for the world's largest winery, E & J Gallo, in Livingston California for a while, plus black iron pipe welding for the same outfit, anywhere from 2" to 12" diameter stuff. The stainless was done with Argon-shielded TIG, with Nitrogen filling the inside of the pipes for a 100% penetration weld with no fill rod and pipe ends machined to have a hairline fit in an alignment fixture. We used a Tungsten electrode ground to a needle-sharp point and the width of the weld bead was less than 1/8" with no buildup above the surface.

If I was welding patch panels onto somebody's vintage Rolls-Royce bodywork, I'd probably use a similar procedure, and the labor charge would be proportional to the customer's depth of pocket. It wouldn't be cheap! For routine body work, CO2 shielded MIG works very well, and it's affordable, and not too hard for someone with moderate experience to learn to do acceptably.
Jerry

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