I've done the metal spraying many moons ago and was never that impressed, but to be fair I doubt we had it set up properly.

We were stuck for a spare pump shaft, so I built up a spare one from a used but nearly good one (we never really threw anything out deep sea), after I stripped the pump that was on its last legs, the shaft in it wasn't as bad as expected so decided to just build it up with stainless welding rods, took some time but once machined it was perfect.......and we still had the spare which had been sprayed.