Thanks, Robert; mapleleaf, I'm just following your thread as its timing is great...hope you don't mind the questions.
If I am reading this correctly, the first tack in our progressive movement from one side to the other side of the panel is extremely important. I do not know the term used, but it should hold/pinch/fuse/anchor the entire panel for the subsequent tacks-correct? My only analogy would be in roof framing & how you'd nail one end of a facial board to a rafter; then worm it up flush for nailing the next rafter, and so on. I'm thinking this method of tack-welding from one end, and working toward the other might help me a lot with fitment.
Also, using the "no-gap" method mentioned above, and assuming the panels suck up (or shrink?) into each other as is common, does "planishing" the weld tacks individually and stretching them out need to be almost immediate; while still warm? I didn't see a picture, but I understand this is a common question regarding the valley, and you'd probably answered it before.
I do know how to make a valley happen.
Brad
