Trying to weld, I’m terrible!
As mentioned, a flattened piece of copper as a backer will allow you to get more heat in the seam without blowing out. It acts as a heat sink. It is also the berries if you blow a big hole, you can weld against the copper to stitch the hole closed and it won't stick to it. Should be videos on utube. 023 wire will work a lot better on the thin stuff too