Thanks Alan. That's good info.
I suspect this is what the p.o. of 83XT4's boat must have meant when he said that the keel was "encapsulated". I can see how confusion could arise. He should have been a bit more specific and added "in epoxy."
Back to the question, I would say that if the epoxy is intact and still adhering, then simply re-painting is all that's called for. If there are some bare or flakey spots, then following Bill Murdoch's advice to use the International/Interlux method of sealing and fairing would seem like a good approach.