Daves tip on leaving the thing alone for a while in between welds is the best tip. DO NOT cool the welds with a wet rag or something like that! That is a BIG MISTAKE and very common. It is not simply "cooling" the weld, it is SHRINKING the metal! Now that will cause warping!

Nope, the simple trick is as Dave pointed out, tack it along the line, then WALK AWAY. Do something else on the car (I'll bet you have a couple of other things you could work on. ) and then come back and weld a couple of quarter inch or so beads on each ends of the seam or one in the middle and one on an end, then LEAVE IT ALONE until you can come back and rest your hand on the weld and feel next to no heat (or nothing, it won't hurt to wait even longer).

By the way, the .035 is a little big. I welded for years with .035 so it does work. But it is carrying more amps, thus a hotter weld. Change to .023 (Which will mean a change in the drive wheel and tip) and you can turn the heat much lower than you have now.

Brian