Last week I tried the Zinc Chromate primer from NAPA. I previously had a supply of "the good ole stuff" from a buddy who worked at Delta Airlines - that primer was very yellow and I swear it would stick to glass! The spray cans were labeled "application by professionals only".
The product from NAPA is tan in color, after applying it to some aluminum parts per directions and allowing it to cure I applied the top coat. After drying I could easily remove it with my fingernail, right down to the aluminum. So I striped it off and washed the part with Alumiprep 33 that I had internet ordered from aircraftspruce.com for my new fuel tank previous to installation. After washing with Alumiprep, you have to rinse with Alodine (also from Aircraft Spruce). I applied both products using 2 hand operated spray bottles from Lowes and got excellent results. The Alumiprep etches the aluminum and the Alodine seals it before it can start to oxidize.
The topcoat for my parts was rattle-can paint - so not as tough as what you are likely considering for your hull. For the fuel tank I used Devtar 5A which is used to treat metal intended for under ground applications - Super tough stuff.