Issue link: https://www.e-digitaleditions.com/i/954267
Coating value is more than just color Powder coat processing of metal substrates for high- value exterior architectural applications has been suc- cessfully happening for decades. The combination of proper design, com- plete and accurate specifications, and the use of professional and competent contractors that use the best processes and material technologies available has resulted in successful powder coated projects all around the world. These successful projects do not happen by chance. They begin with a solid, reli- able, and pragmatic design specification plan that is reviewed and approved in d e t a i l b y c o n t r a c t p r o f e s s i o n a l s throughout the build process. Unfortu- nately, not all projects end on a happy note. This article highlights the impor- tance of proactive planning and com- munication between designers, engi- neers, and contractors throughout the planning and building process to ensure quality and avoid preventable failures. Back story The silver powder coated finish on select aluminum and steel components of the condominium building pictured in Photo 1 was reported to be defective due to the discovery of coating adhesion and metal corrosion problems by the tenants. The building is located in Northern California just a short dis- tance from the Pacific Ocean. The powder material was a silver metal- lic color in polyester TGIC chemistry that was selected from a stock-available powder material that closely matched the liquid applied fluoropolymer on the windows and building panels. Coating adhesion and corrosion fail- ures began to occur on these compo- nents within a couple of years after completion of the building. After years of expert inspections, field and laboratory analysis, depositions, legal discovery, and deliberation, it was determined that there were many con- tributing causes of the adhesion and corrosion failure. The failure resulted in the need to remove and replace the building components. The failures occurred on the aluminum balcony rails, as shown in Photos 2 and 4, and the perforated steel privacy screens, as shown in Photos 3 and 4. The powder coatings on these alu- minum extrusions and steel perforated Michael W. Cravens Powder Finishing Consultants and IKON Powder Coating Coater's Corner Coater's Corner Photo 1 Evidence file photo: Building POWDER COATING, March 2018 31