An aluminum alloy was coated with Minimox® solution and put into service in an oxidizing atmosphere. The assembly was exposed to a hot acidic atmosphere with cyclic corrosion conditions. After long term exposure, the cross sections below were obtained by an outside laboratory. The Minimox® nanocrystalline treatment demonstrated corrosion resistance under these hot, acidic conditions. The customer tested over 60 aluminum coating and alloy systems, and Minimox® solution and only one other system were deemed to have passed the test requirements.