I'm not much of a welder myself, but my 2¢ is you need
less wire speed, near the lowest heat, faster movement, the wire size shouldn't make much difference, except the bigger the wire, the slower the feed needed .... you may be trying to run too long a continuous bead, stitch an inch, skip 3, do another inch, go back and fill some, etc, never be stationary or weld a long joint in one pass - and expect to give the grinder a workout regardless
.... using an extension cord will just overheat the power circuit, the control on the box is all that can reduce heat .... and rusted metal is a problem even for pros
Bill
