mugsy, if you could
totally eliminate one of the 2, you might stop further rusting, but what I'm saying is that you can't
totally eliminate the oxy [
which is the critical element ] because it has become part of the rust that's there, and the oxidizing process can continue w/ very minimal moisture, which also will prolly be there unless you bake the piece before you coat it [called ambient humidity, and salty air like in your area works especially well] - the oxygen becomes part of the material - when you coat it w/ something you will supply a bit more moisture to maintain the electrolysis, and how long it will be before it pops the paint may vary, but it'll happen - that's why good shops use a metal prep like phosphoric acid, to convert any stray iron oxide in the little pits and crannies to an inert form that can't continue growing under the paint - you can
inhibit rust by encapsulating it, but you won't 'prevent any further rusting'
Bill