I have been doing some patch work using mig welding, flux core wire. My problem is with burn thru or blow thru. If I am using a slightly higher gage sheet, patching to the original on the car, unless the mating surface is exactly right the original, lighter sheet wants to burn thru. I know set up is key. Everthing must be clean etc, no gaps if possible. Unfortunately these patches are on the unibody at the point wher ethe lower fender bolts go. These patches have several bends and to make a patch with no gaps is extremely difficult. I got one side done but was wondering if anyone had any techniques they use when doing similar welding.
Thanks!!