Mike, I wonder what rod would be best to patch them with? 9018 is obviously hard (definitely pre-heat) and I'm sure there's some other rods out there that would be even better. I've got some super hard exotic alloy rod (ass rod, if you ask me, but you'll flat-top it anyway with a grinder) I used to "hard-face" over coal-burners I was rebuilding in a coal-fire shut-down recently in Chicago (boiler wall). You're welcome to try some out if you want. I don't know why I kept them, but you might.

Ivan, a rod keeper