Kynar, AAMA 2605, AAMA 2604 and standard powder coat. Is there a difference?

Why the frame finish matters.

The paint on an aluminum impact window does two jobs. It gives the frame its color, and it protects the metal from sun, rain and salt air for as long as you own the house. In South Florida the sun is strong all year, and many homes sit close to salt water. A finish that fades, chalks or wears thin will make even a well-built window look tired. Frame finishes are graded by a set of industry specifications, and the grade you choose often decides how long the finish warranty runs and whether it still applies near the coast.

What AAMA 2603, 2604 and 2605 are.

AAMA (the American Architectural Manufacturers Association, now part of FGIA, the Fenestration and Glazing Industry Alliance) publishes three voluntary specifications for factory-applied organic coatings, meaning paints, on aluminum extrusions and panels. Each one sets test procedures and pass marks for color, gloss, chalking, erosion and corrosion resistance. They are performance standards, not brand names or paint types, so any coating that passes the tests can carry the number. FGIA describes them as the good, better and best tiers of aluminum finishes:

• AAMA 2603: pigmented organic coatings, the basic tier.
• AAMA 2604: high performance organic coatings, the middle tier.
• AAMA 2605: superior performing organic coatings, the top tier.

How the three tiers compare.

The biggest difference is outdoor exposure testing. Painted test panels sit on an outdoor site in South Florida, then are measured for fading, chalking (a powdery residue as the paint surface breaks down), gloss loss and erosion (loss of paint thickness). Fading is measured as Delta E, a number for how far the color has shifted. A 2605 finish has to hold up for twice as long as a 2604 finish, and keep more of its gloss.

What Kynar 500 means.

Kynar 500 is Arkema's PVDF (polyvinylidene fluoride) resin, used in architectural metal coatings since 1965. Arkema does not sell the paint itself. Licensed coating makers formulate it, and a coating sold as Kynar 500 must contain at least 70% PVDF resin by weight and meet AAMA 2605. Liquid 70% PVDF paints are the classic AAMA 2605 finish; PPG's Duranar coatings, for example, are built on 70% fluoropolymer resin and meet 2605. A 50% PVDF paint is a 2604-level product. So "Kynar" on a quote usually means a 2605 finish, but it is the AAMA number that sets the performance.

Powder coat or liquid PVDF.

Powder coat is a dry powder sprayed onto the aluminum and baked into a film. It contains no solvents. Liquid PVDF is a solvent-based paint, sprayed and oven-baked in the factory, and metallic colors usually get a clear topcoat for protection. Neither method is better on its own. "Powder coat" by itself says nothing about grade, because powders are made for every tier, so always ask for the AAMA number:

• Standard polyester powder: AAMA 2603.
• Super durable polyester powder: AAMA 2604.
• FEVE (fluoroethylene vinyl ether) fluoropolymer powder: AAMA 2605.

Salt air and coastal homes.

Salt spray is hard on any finish, and salt deposits left on a frame keep attacking it between rains. That is why the finish tier matters most near the water. Some warranties draw the line by finish and distance from salt water. Every Mr. Glass line comes with AAMA 2604 powder coat as standard, and its AAMA 2605 upgrade is the only finish still covered within 2 miles of salt water. ES Windows recommends Kynar paint near the coastline. If your home is on the water, on a barrier island or close to the beach, plan on a 2605 or Kynar finish and confirm the warranty terms for your address before ordering.

How warranties tie to the finish.

Finish warranties are written per finish, not per window, so two frames from the same brand can carry very different coverage. ES Windows' Multimax line comes in white and bronze only (AAMA 2604 paint), while Prestige and Legacy come with Kynar finishes as standard. Mr. Glass offers AAMA 2604 powder coat as standard, with AAMA 2605, Kynar and woodgrain finishes available.

Caring for the finish.

No finish is maintenance-free. Rinse frames with fresh water to remove salt and dirt, wash with a mild soap and a soft cloth, and avoid abrasive pads and harsh solvents that can scratch or dull the paint. FGIA publishes a cleaning and maintenance guide for painted and anodized aluminum (AAMA 609 and 610). Some warranties make cleaning a condition: ES Windows requires that windows and doors be washed with tap water at least every six months, with proof of cleaning, for the warranty to apply. Keep a simple log with dates and photos.

Choose the finish, then confirm the product.

For most inland homes a 2604 finish is a sound choice. For waterfront and beach homes, a 2605 or Kynar finish buys longer color life and, with some brands, keeps the finish warranty in force. The finish does not change a window's impact or pressure rating. That comes from the product approval, which governs the exact product, size and glass for each opening. True Impact confirms the approval, the finish and its warranty terms for every opening before you order. Ask us for a side-by-side quote.