Sorry I'm so slow to get back...
ZR- I've also seen alligator clips used- often uninsulated (remember, welders have good, thick, dry gloves)
CT- I agree with your desire for safety. Even following your advice, the guy will either work with the front removed from the panel, or punch a hole in the side. Care to guess whether he'll plug that opening when he's through? Oddly enough, I have never seen any kind of "portable sub-panel" or electrical supplies at a welding supply shop.
Let's face it: the guy just wants to do his job and go on (as 3rd degree noted).
This is not, and never will be, a perfect world. There is always room for improvement. I believe that the need to perform maintenance, etc., is common enough to warrant manufacturers considering it in their designs. I also believe that some tasks -welding, for instance- occur with enough frequency that they ought to be anticipated- removing the need for such jury-rigging.
If necessity is the mother of invention, let's celebrate this Mother's Day by removing a few "mothers" from our jobsites!
