I agree, but will disagree. Flux welds a little hotter than mig. Just like running straight co, runs hotter than 75-25 gas on a mig. Now, I will say, it has to be Clean, he better have his A-game on, and he better have the right wire. As long as he stays away from the single pass wire, he should be ok. But that turns around and complicates the other passes. Hard to control warpage with 3-4 passes. Can I ask a question? What is with cutting the middle of the tube? Why not just the outside end, put in a new axle end, weld it in and call it a day?