Welding questions

0.30 wire is not the best for sheet metal try using 0.24 or 0.18 . the weld in the pic is done with a mig. just get a piece of scrap and try heat testing until the wire burns good and smooth the smaller wire will burn easy and give you less trouble with thin metal. when you turn the heat up you must turn the wire speed up and slow down wire speed when you turn heat down . practice and get your heat and wire speed right .