Good project. I'd suggest going to at least an 80 cu. ft. cylinder so it will last longer. I bet the price difference would be minimal as well. When I expanded your picture, it looks like you were burning a little cold. Try turning your wire speed and volts up a bit and with the type of MIG welding you're doing, it's always a good idea to twist your wrist side to side or go in circles to be sure you get proper fusion on both sides of the joint.