The Powder Principle

Learn the different types of powders, colors and performance levels

Powder coatings are appearing on more and more building specifications. A factory-applied finish, powder coating is perfect for metal substrates. This usually means aluminum and steel, so powders can be used on most metal applications in a building’s construction. The most common applications include curtainwalls, window walls, mullions, windows and doors, fencing, railing, HVAC units, lighting and interior decorative pieces.With such a wide variety of applications, including both interior and exterior uses, ensuring you have the right powder product type is essential.

Colors

A common mistake in a building spec is to simply call out for a powder color.Powder coatings can be made in thousands of different colors and effects,including sparkling metallics, micas and textures. Getting that color in theright product type is key to the success of the coating’s performance, and thesatisfaction of your client. Often the cheapest powder in the right color ischosen. However, if that powder has been designed for interior uses, but is being used on exterior applications-and therefore subjected to harsh sunlight, salt air, humidity and many other factors that cause stress to a coating-this is where problems can occur.

Likewise, the spec may call for a for a two-coat system or equivalent system. Certain types of powder coatings, based around fluoroethylene vinyl ether (FEVE) resins, can actually achieve the same or better performance in a single coat, so don’t let that worry you.

There are many different powder product types with varying benefits, but there are three architectural grade powder products that are ideally suited to the construction market. The entry-level product is a Standard Polyester powder. Super Durable Polyester powders are manufactured to offer five times the weathering protection as a Standard Polyester, and Fluoropolymer powders are the 70 percent liquid polyvinylidene fluoride (PVDF) equivalent.

Specification

You may also see the American Architectural Manufacturers Association (AAMA) coating specification quoted in the building spec for coatings. A common misconception is that the AAMA specifications are just for liquid coatings. Not true. The AAMA specs are for both liquid and powder coatings. It’s no coincidence that there are three architectural grade powder types and three AAMA finishing specs. Most manufacturers of powder coatings produce their architectural grade powders to meet the performance requirements outlined in these three AAMA specs.

The AAMA specs set out test methods and performance requirements, but most powders will exceed these performance requirements. For example, an AAMA 2605 coating is required to pass 10 years of Florida weathering and color and gloss retention, but a 20-year warranty is possible for these coatings when applied to architectural aluminum by a certified applicator. In terms of performance, powders perform just as well, if not better than competing liquid coatings.

Many architectural grade powders are thermosetting (versus the liquid thermoplastic PVDF system) and this ensures maximum film integrity and superior protection. The tough, thermoset film offers significantly better scratch and abrasion resistance, reduced susceptibility to dirt and mildew growth, and this improved performance against damage means a reduction in replacements and touch ups.

Environmental Advantages

Powders also offer significant environmental advantages including low- or no-volatile organic compounds (VOCs), lower carbon dioxide emissions than competing finishes and no chrome pretreatment or primer is required (chrome free pretreatment will still give AAMA 2605 level performance, and most powders do not require a primer on aluminum). In addition, no toxic waste or landfill is created during application, unlike competing coatings, and powders demonstrate superior environmental performance over liquid or anodized finishes in every LEED category. For so long the environmental advantages of products have been dismissed as nice to have, but with architects and owners increasingly designing with sustainability in mind, offering the same colors and performance levels without the environmental impact adds real value.

Not surprisingly, achieving this first-class performance requires quality pretreatment and application, especially for exterior applications. When it comes to AAMA 2604 and 2605 grade powders, ensuring a quality coater who has demonstrated its ability to apply powder that can pass the tests outlined in the AAMA specs is essential. All good powder manufacturers will have a certified applicator network consisting of coaters, extruders and fabricators who have been thoroughly tested. This ensures that their pretreatment, application, curing oven and quality levels are of a good enough standard to pass the strict performance requirements of the AAMA specifications.

Overall, powder coatings are high-performing, sustainable, durable and hard-working coatings available in thousands of colors and effects. Choosing powder has never been easier.

Fiona Levin-Smith is director of marketing and specification at IFS Coatings Inc., Gainsville Texas. To learn more, call
(520) 345-7513 or visit www.ifscoatings.com