I have a 135 mig,welding in trunk floor patches (20 ga), 6mm wire, set @temp E , speed 4, gas @15 to 20 cfm. Car is on a rotisserie (upside-down @45 deg). Welding down I had to increase heat a little, ok penetration, found if I held the tac a little longer the weld flattened out nice. Welding inside the trunk over head @45 deg. I increased heat a little, weld balls up poor penetration, increase gas = same, increase wire & still balls up. I held tac longer it blows out. I have no problem welding thicker metal in & out of position, any ideas or advice?