From the moment painted coating is applied to a surface, it begins to degrade from exposure to the elements. Over time, the difference between a coating’s original and current color becomes more pronounced. Selecting a coating designed for the environment where the painted aluminum product is installed, and taking steps to protect it, will help ensure color that lasts as long as possible.
When discussing how long a painted coating’s color will last, we usually refer to “fade.” Fading occurs from the oxidizing or leaching of pigment from the paint, causing its color to alter from its original application. Intense UV radiation (i.e. daylight) also causes fading. All paint color will fade eventually, but the degree of fade can be reduced with knowledgeable selection and basic maintenance.
Specifying for Fade Resistance
The American Architectural Manufacturers Association’s industry-leading performance standards – AAMA 2603, 2604 and 2605 – for architectural painted coatings specify color retention in terms of Delta-E (dE). A dE is a unit of measurement between two colors where 1.0 is the smallest difference a human eye can see. As time passes and a finish drifts from its original hue, its dE increases.
- AAMA 2603 requires that a paint show only “slight” fade after one year. This pertains to baked enamel coatings typically used for interior application where color retention is not a large concern.
- AAMA 2604 requires that a painted coating must not fade more than 5 dE over five years. This pertains to 50% PVDF resin-based coatings and typically is used for storefronts, doors or other high-traffic areas.
- AAMA 2605 requires that a painted coating must not fade more than 5 dE over 10 years. This pertains to 70% PVDF resin-based coatings and typically is used for curtainwall and window wall on monumental architectural projects.
Formulating for Vibrant, Durability
The composition of a paint’s pigments will influence how quickly it fades. Inorganic pigments fade more slowly than organic pigments. Some brighter, more vibrant colors – such as bright red – traditionally use organic pigments to achieve their desired hue. The organic pigment’s greater susceptibility to fading can be combatted by applying a clear-coat over the topcoat of paint. This helps minimize UV exposure to the more vulnerable pigment.
Once applied, even a durable finish will require occasional cleaning to slow its fading. Avoid cleaning a coated surface with strong acid or alkali cleaners. Instead selecting a mild soap solution for washing your finished surfaces.
Learn more about color retention and Linetec’s paint finishing services by clicking here . For personalized assistance in selecting the right coating for your aluminum building products, please contact Linetec’s regional sales managers , email sales@linetec.com or call 888-717-1472.