Q: I have a question regarding Qualicoat Class 1 approval. For polyester-TGIC powder coating, the gloss should not be less than 50% after 1000 hours Xenon Arc exposure. I want to know if a powder based on a standard polyester-TGIC resin will pass this test (approximately equivalent to one year Florida). Or do we need another type of polyester resin for Class 1?
A: A standard-grade TGIC-polyester will meet the Qualicoat Class 1 specification. Qualicoat Class 1 basically requires a powder coating finish to maintain color and gloss after one year of exposure to a south Florida climate. The specification also requires chemical resistance, so it is important to confirm mortar and sulfuric acid resistance performance.
In addition, it is important to select your polyester resin from a reputable supplier. Furthermore, make sure that the pigments and additives in your formula are weather resistant. Some waxes are not UV durable. Keep in mind that many organic pigments will fade from one year Florida exposure. It’s important to choose your additives and pigments wisely.