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Table 1 24 POWDER COATING, September 2016 Fastener options and dissimilar metal corrosion Architectural finishing of products that are expect- ed to withstand the stress- es of outdoor weather environments requires special attention to all details in all phases of design, pro- cessing, installation, and customer care. The most important physical attribute of protective coatings for architectural applications is to prevent corrosion dur- ing the expected service life of a product. Not to understate the importance of color and gloss retention, but corrosion is considered to be the cancer of all metal finishing failure modes. When corrosion is determined to be the failure mode within a given warranty period, the failure is often referred to as cata- strophic. Engineering a complete product for a particular environmental classification requires planning in all phases of the process, including metal selection, manufacturing fabrication, finishing, and assembly. The four general phases of manufacturing an architectural prod- uct are: • Phase 1: Product design and planning • Phase 2: Product fabrication • Phase 3: Product finishing • Phase 4: Product assembly Each of these phases would have many subtopics that would require the proper amount of planning, testing, and evalu- ation of options in materials and process selection with consideration of the expected service life of the end use prod- uct. For long-term product success, each phase of the engineering process must be complete and accurate. Prob- lems can occur in any one of these phas- es that could adversely affect the overall quality of the final product in terms of service life. The result of this planning, testing, and evaluation should yield a series of detailed project specifications for contractors to follow. Previous architectural finishing related articles have focused on the design, fab- rication, and product finishing options, but little attention is ever given to the proper choice of assembly hardware, fasteners, and other metal components that are in contact with the substrate and the protective coating. Product assembly after the application of the protective finish is seldom given proper attention and is often found to be the primary or contributing root cause for premature corrosion failures. This arti- cle will focus on a common problem that is often overlooked by design engi- neers and installation contractors dur- ing phase four — product assembly and hardware selection. Coater's Corner Coater's Corner Michael W. Cravens Powder Finishing Consultants and IKON Powder Coating Corrosive Rating General Description Category A Very Low Indoor Climate Controlled – Clean Atmospheres B Low Indoor Uncontrolled Climate – Dry Rural Areas C Medium Low Salinity Coastal Area – Humid Interiors D High Coastal Areas – Damp Interiors E Very High Coastal Areas – Damp Exterior EI Very High Industry Aggressive Industrial Areas EM Very High Marine Marine Coastal – Off-Shore F Very High Tropical Inland Tropical