Wrap it with something? Although, if I remember correctly, there are stainless welding rods....different metals for different welding applications. The welders in this thread can correct me if necessary
I just got a load of heat shrink tubing for fixing kinked / frayed charging cables & the like. They're spectacular, with a coating of glue on the inside & double walled material. Very much multipurpose.
Just slip over your metal rod, crank up the heat gun for a minute or so & away you go. The glue inside melts, so the tubing grips what's under it really well, and the tubing is impermeable. The stuff is really tough, and you can use more than one layer to thicken the hanger tool up, or layer something underneath the tubing to make it fatter.
Don't know how long it would last, but I'm assuming a fair length of time.
