Hi, I'm welding a piece of this in an awkward place on the inner arch area of a car. I've tried adjusting wire speed and amps. I'm finding that using higher amps makes the welder hiss and not really weld but just melt the metal. It's a new RTech MIG 180 using 0.6 wire and 95%/5% gas. The front side looks pretty good but the backside has nearly 0 penetration. One issue I know I have but not sure if it would contribute to to it or maybe cause it (as I can get decent penetration on a test piece not on the car) is that I can't clean the other side of where this piece connects to very well at all as space is very limited. Need advice, please!