If I tiggyed it, I would use the .040 tung, #3 cup and 40-60A.
If I torched it, I would use a #0 tip,
Tack and planish full length, either method, until tacks are 1.5-2in o/c.
Then start at one end and weld 3in, and then hot planish - with a rigid straight edge on the panel
every minute. Repeat until done.
Hint: I do not let the panel get ahead of me.
P1100551 copy.jpg
THIS IS NOT A LONG WELD. (Steel panel for an old XKE.)
I've had to weld a lot of flat panels, and have gone to file finished in most cases...
Sedans, coupes, vans, panel trucks - sides, roofs, hoods, floors, firewalls. Steel and aluminum.
This is what works for me, and is a variation on the
different styles/procedures I have learned from the senior metal men, over the years.
Methods are generally the same -
how you combine them is your style.
(p.s. - I have long arms w/6.5ft total, fingertip to fingertip)
I'm not much good working inside trunks and engine compartments, though.