You might want to forgo the etch and alodyne step if you are going to shoot an epoxy primer. Aircraft aluminum is clad with an alloy that is harder than the base metal alloy while marine aluminum is just plain aluminum the entire thickness of the sheet. The harder alloys are more suseptable to oxidation therfore require the etch and conversion treatment prior to paint so the primer layer has tooth to adhere to.
At least thats how I remember it from my Navy corrosion control school.
G