Just welded one of my doors up.
Given that mine rusted from the outside I just cut a strip of 20 gauge and just stuffed it inside the door tacked it in place and just welded the holes up with the MIG.
Took about 2 hours to grind it smooth, nothing warped.
Just need to paint the inside with POR15 so it doesn't get any ideas about rusting from the inside.
I like to bush some on the lap joint to the skin to get the capillary action to pull it up between the skin and the rest of the door.
