Just went back out and sliced a couple of hunks off a (badly bent up) hood from a '95 Mustang. Ground & polished. got rid the paint and etc. And tried putting them together. Still using the .035 wire and gas turned up to 15
Power turned up to 105 amps
Ran a bead around the "seam", released the clamps and said something that sounded a lot like "whale oil beef hooked"
They are stuck together! Ground down the beads and still could not pry them apart! Cut through the beads with angle grinder and - wow!
Tomorrow I'll see if that was a one-off or if it just might be repeatable. (and I guess I'll try my stick welder on the heavy channel iron for the window frames for the burglar bars - otherwise its "Yoo hoo neighbor?"