Though more research needs to be done to determine the total environmental impact of different aluminum finishes, from a finisher's point of view, anodizing does far less damage. The chemicals from anodizing can be used by municipal waste water treatment facilities. The aluminum sulfate from anodizing plants' effluent actually improves the solids settling efficiency of some waste water treatment plants. With aluminum the pretreatment is of utmost importance. This is why organic coatings for aluminum should be factory applied.
Resins are often the weak link in an organic coating system.
Some resins, such as PVDF, have outstanding weatherability, while epoxy coatings are meant only for interior use. There are many resins available for architectural use such as Urethanes, Polyurethanes, Aliphatic Urethanes, Polyesters, Silicon Polyesters, Polyester TGICs, PVDF, etc. Only a few of these coating systems will last for more than five years in exterior architectural applications. An important aspect of AAMA 2605-98 is the requirement for actual ten year exposure in South Florida. It is a good idea when evaluating different coatings to ask to see the results of Florida exposure.