Welding newbie need advice
I am new to welding, took some classes years ago and have forgotten most of it. I have a cheap HF Mig welder. It works great, but the welds are not pretty. My big question is this: The bike frames I have vary in material. one of the frames is an old french thing with nice heavy steel frame, I weld a walmart special with the thinner oversized tube to it and get crappy looking welds of questionable integrity. The problem is that the different gauge metals, if I set it hot enough for decent penetration of the french frame, it just melts the walmart tube, if I turn it down to for the walmart tube, then I don't get penetration on the french frame. any suggestions? I have been laying on the welds and grinding down, an it is ugly, but it seems to hold, but I figure someone might be able to give me some pointers for better welds and less grinding.