I seem to recall a certain someone, whose name rhymes with Sway, advising you to apply Ospho to that keel when stripped. Ospho is the commercial grade "rust restorer" containing phosphoric acid and you'll recognize it by it's mildew green color. It dries black after it has neutralized the rust.
The advise above, about the application of epoxy immediately after stripping is correct, particularly in a humid, salt air environment. Rust never sleeps, heck, it never even cat-naps!
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.