Jul 1997 I have been unable to locate any hard data on the long term resistance of certain aluminum alloys in a salt fog environment. We need a low cost finish such as iridite, but able to withstand up to 5 years in a warm, salty environment.
Painting is expensive.
I would like to see evidence of the corrosion resistance of these alloys after 5 years or more in a salt environment when coated with iridite, or anodize, or any other low-cost suggestion. I have an immediate need. Jul 1997 I would be reluctant to use either 7075 or 2014 in a seacoast environment even with a protective coating due to the risk of exfoliation corrosion. 6061 is not susceptible to this type of attack, but may sustain some minor pitting and surface deposits even with anodizing. Look in the literature for references to experiments at Kure Beach.