This tip was given to me by an experienced body goy - supposedly flux core with shielding gas gives best results. Anybody heard this and how/why does it work better? All I can say is I need all the help I cam get - I SUCK at welding. My liittle patches are killing me - I've warped metal and I've tried to fill the same small pinholes three and four times, weld, grind, weld, grind, weld. Am I expecting too much ? If I've got a dozen or so pinholes around the weld - should I move on to fiberglass ? Not fun - WARNING: if your a perfectionist - don't try this on your own without experienced help or classes!