There are some manufacturers using poly vinyl difluoride (PVDF) fluoropolymer resins, which similar to their liquid equivalents, are two coat systems, however, this is not as common as fluoropolymer powders using FEVE resins.
Similar to equivalent liquid PVDF fluoropolymers, FEVE fluoropolymer-based powder delivers a superior performance coating, is available in the same colors, metallics, and even textured effects, and often comes with a 20-year warranty when applied by registered applicators to architectural aluminum. There are some incredible buildings around the world that have utilized FEVE fluoropolymers on facade elements such as curtain wall and windows.
Super durable powders
Many super durable polyester powders will meet and exceed the performance requirements of AAMA 2604. They use a super durable polyester resin to deliver great exterior weathering and often come with a warranty when applied by registered applicators to architectural aluminum. They are also a very hard, tough, scratch-resistant film, and for this reason, are often used on commercial storefront and windows. There are also many examples of super durable powders being utilized on some interior applications where long-term color retention is beneficial, as they offer great value for money.
Standard polyester powders
Powders utilizing a standard polyester resin system will often meet and exceed the performance requirements of AMAA 2603. The 2603 performance specification has a more limited exterior weathering requirement; therefore, this type of coating is often used on interior applications or on lower value exterior applications. Standard polyester powders are available in an enormous range of colors and special effects. Alongside the metallics and fine textures available in the exterior grade powders, hammerstones, veins, heavier textures, wrinkles, and even glow-in-the-dark formulations are possible in a standard polyester formulation.
It is not a given that all powder formulations utilizing these types of resins will meet the AAMA performance requirements outlined above, so it is always worth noting the performance specification (e.g. AAMA 2604), as well as the type of architectural powder coating.
The key differences between liquid and powder performance coatings
Powder coatings on aluminum are often a single coat application. This includes an AAMA 2605 level as well. FEVE fluoropolymer powders will deliver the same performance as their equivalent liquid PVDF coatings, but in a single coat. A primer is not required, nor is a clear coat, even with metallic/mica effect coatings. The reasons for this are differences in how these coatings are made and the ingredients used, but powder coatings are most often a single coat application.
A two-coat application is common with steel. The pretreatment options for steel are very different, and as such, a powder primer is often recommended with steel substrates. If corrosion is a concern, then a zinc rich powder primer can be utilized. The powder topcoat is then applied.
