This guy has some good videos
https://m.youtube.com/watch?v=-DvzUkMQGlk
Some good tips
When I weld on panels I always butt weld , and I use stainless wire so that my welds dint get rusty It’s hard as hell to grind though so keep your welds as small as you can. Low heat so that it doesn’t weld hood til it fairly hot will help with burn through and if you can back it up with copper that’ll help with burn through as well .
I also like to lay the gun on an angle across the butt joint so that the weld starts on full metal and ends in full metal and lays the rod across the joint. You dint get as much penatratiin this way it kind of lays the weld across the top but sometimes it’s necessary w thin metal
https://www.eastwood.com/stitch-weld...fb605bb2f1b360
Something like this can help hold panels together can’t really use clecos and but weld