welding coated headers

If it is just a gouge and not through just leave it alone, if it has to be repaired just clean it up so it can be welded. Then I would use Eastwood's silver high temp coating P/N 101752 in a can and just touch it up with a brush. I have done whole exhaust systems with that and it holds up great. I have to weld a bung in my collector soon and will be doing that very same thing.