Welding

I do this a lot at work. It's not easy to weld galved steel, so either grind/sand off the zinc on the nut (not the easiest to do if they're small!) or use a plain steel nut. If the tube is galved, sand the galv off that too around the area of the weld.

The fumes from zinc are toxic so wear a mask and weld in a well ventilated area.