Interesting technique! The problem with skip-welding like that is there's a definite possibility of getting seep leaks of coolant where the welds overlap. Here's an obscure little fact some folks don't know- - - -once a root pass of nickel welding rod is laid down and well-bonded to the cast iron, regular mild steel welding rod can be used for an overlay. I like #7014 rod for a cap pass over the nickel rod. 7014 can be run with an AC buzz box welder like the little Lincoln tombstone style welder, and the bead lays down flat with a slag layer that curls up and almost falls off by itself. I like to post-heat the workpiece with a torch, and then bury it in a pile of sand overnight for a slow cool-down.
Jerry
