Okay what I am tring to do is weld a donor roof on my 1929 ford model A .... since it is sheet metal I would guess I need do spot weld all over the place thousands of them so I don't distort the roof or can I do some small welds just moving around? anyway I have a snap on welder I had the heat at 7 and the feed at 7 with the gas at 20 inches... it does have settings for spot, stitch and continous weld.. with spot with settings upto 4 seconds... I had it on contious weld and was able on practice sheet metal get it to get good penetration where if i bent the sheet metal back and forth it would break behind my spot welds... there is a lot of extra weld on top is this normal or is there a way to cut down on the extra metal and have a more of a flat spot weld? also sometimes the spots would look like "puter" very rough and pourus what causes that? any help on setting this welder up and getting a better weld would be appriciated.... I don't want to touch the welder to the car till my welds look a lot better! but I don't want to use a whole spool of wire and tank of argon co2 tring to get this right....

thanks,
simon