shaving my drip rails, 73 dart

Well screwed the pooch pretty good first time around...Got the metal to damn thing, and mig is burning through it. had to switch to .25 and lowest setting..burning a bead good now, should say a tack...tack tack tack...but im have to rebuild the metal, cuz its just so thin burning through. I may have to use a a filler strip.

All i can say so far is, don't screw up like I did and get the metal to thing trying to "shape the rail" as your grind if off.