It’s important to know all the facts when choosing the right paint system for your metal roof. There are three primary resins used for coating exterior metal products: Polyester, SMP, and Kynar. Polyesters offer a hard, scratch-resistant finish and a wide range of gloss, but are prone to chalking when exposed to UV. Polyesters have been greatly improved since their introduction in the 1960s, however, with higher molecular weights and longer polymeric chains that create stronger, more UV-resistant bonds. However, polyester remains an older paint system used mostly on utility grade panels and subject to noticeable fading in as little as 3 years. Another is PVDF (Polyvinylidene fluoride), popularly known by its original trade name, Kynar. It is a kind of fluoropolymer, a family that includes Teflon. PVDF resin has excellent chalk resistance and gloss retention, as well as stain and chemical resistance. It is softer than SMPs and polyesters, however, making it relatively easy to scratch during transport or installation and it is also more expensive than the more durable SMPs.
SMP (Modified Siliconized Polyester) creates a middle ground between PVDFs and polyesters. SMPs use polymerized silicone to improve polyester’s chalk performance and gloss retention. Most SMPs now contain 30 percent or less silicone. SMP paint systems offer an affordable choice in paint systems for Metal Roofing and are a vast improvement over the original polyester paint system of the late 90’s and before. SMP (Modified Siliconized Polyester) paint systems have improved in both stability of color and reduction of chalking. SMP paint systems remain tough and durable over many years of sun exposure. The new Valspar WeatherXL® paint system has taken these assets even further and in many instances, is the best choice over Kynar paint systems.
For many years, Kynar has been a benchmark to which paint systems were compared to for resisting chalking and fading on metal exposed to weather; the only major down fall is that Kynar, a form of epoxy paint which remains soft, is subject to damage and scratching easily, exposing the material underneath to the weather. For metal architecture, few elements are more detrimental and corrosive than sea salt and spray. Kynar has a resin that protects the structure’s exterior from harsh water and salt spray for those near the shore line. Although Kynar is still the best choice for some metallic and bright colors, distributors and manufacturers of Metal Roofing have been known to oversell the Kynar product when it may not be in the best interest of the consumer.
1st Coast Metal Roofing recommends Valspar WeatherXL® in most cases. It’s proprietary resin creates a hard-wearing, no maintenance finish that exhibits remarkable color and gloss retention, superior chalk resistance and resistance to stains, abrasions and metal marking. WeatherXL coatings are resistant to many elements found in the environment such as air pollution, acid rain, and general airborne dirt. This technologically advanced paint system has outstanding color consistency and is ideal for quality metal roofing at a great price.
If you’re interested in more information about the WeatherXL paint system or which paint system is best for your application, 1st Coast Metal Roofing Supply is here to help!
Contact us today @ 888-211-9243.