A buddy of mine wanted me to do a patch job on a family piece (metal bird). I have done some work for him in the past with no problem (usually yard art). This thing is kicking my ass. I've got a Mulitmatic 220. I'm alright with mig but < 1 month with tig. I made a plate out of 16 ga and have the feet down but the body is hella thin with paint. I'm all ears on what to do here. Mig is nasty (which is odd) and tig just melts the thin metal on the bird.
since I can't figure out how to post pics the bird is 26 ga and the plate is 16 ga.
One amp per .001" =63 amps. Puddle on the thicker piece, get some filler in there and just wash the puddle over to the thin stuff and let it just kiss the thin part. Be ready to poke your filler into the thin part if it starts to blow away.
Also, I have had a lot of luck TIG brazing with silicon bronze on small ornamental pieces. It is more forgiving on very thin, non critical parts. Just keep the arc on the bronze and lead it around. The puddle transfers the heat to the base metal, the arc will blow right through. Be patient, let it cool of it gets away from ya.
Heres a couple of Jodys vids that I think might help.
Hope this helps.