Lincoln Pro Mig 140 - How to weld square tubing. HD

I am mig welding 2 inch by 2 inch steel tubing; this is how I made a power weight lifting gym, but using arc welding; I am using .030 steel wire and 75 / 25 argon / co2 gas at 22 CFH rate and 5 FPS wire feed. I prepared the steel using a abrasive chop saw and finished edges with a grind stone and wire brush. Over 540 HD Video