i had them sand blasted and then used cold galvanize spray paint,i put on four coats , and then went with the color coat (gold) and put on another three or four coats, and then i went with a clear acryllic coat, another four coats !! i bought all the paint at Kragens and did not bake anything. if you try to bake the tanks be careful of the temp, you will lose the temper of the steel at around 900 degrees . that is why i didn't go with a powder coat or hot dip galvanize proccess, they get to close to the high temp level of the tempered steel. as far as the ocean eating through the paint, i imagine that eventually the paint will wear down or chip , in places like where the strap buckle goes around the tank ,and around the very top flat surface where the valve mates to the tank,(especially the lip ) . but for about $10-15 bucks a tank,i will just sand down the worn out spot and re-paint it . ask your local dive shop how they feel about painted steel tanks though, some will not fill them . i fill my own nitrox so i don't really care what they have to say !! make sure that you can see all the stamped numbers and letters on the top of the tank ,(hydro dates and tank info) if it is just the plastic coating that is coming off, why not just hand sand the outside and apply the clear acrylic if it is not down to bare metal ? i live in Chula Vista and if you want to see how i did mine come on by (P.M. me for a number)
steve m