The PPA 571 coating protect metal fencing from corrosion for 15 years

Knowing AAMA Rating in Powder Coating Application

Posted on: November 27th, 2016 by byersbushblog

If you are not part of the powder coating industry you wouldn’t be aware that there are differences in the quality of the coats.  But then again, if you are not in the powder coating business, would these differences even matter to you?  Actually it should.

For example, you must be aware that powder coats are designed for specific applications so you cannot use once formulated for metal furniture and appliances to coat railings.  How are the quality of the powder coats determined?  Who makes the determination?


When it comes to the determination of the quality of powder coats, the American Architectural Manufacturers Association (AAMA) makes use of a rating system to distinguish between different coating materials.  Normally, powder coat ratings can fall under 3 categories based on the quality of the finish.

This is determined by the AAMA following demanding testing procedures to uncover the durability of the powder coats and how well they would look after some time.  Factors like color retention, dried paint thickness, and gloss retention are some of the factors taken into consideration.  Accelerated testing procedure is also used to determine if the powder coat can hold up against the impact of humidity and salt spray.  The levels of acceptability are also defined by the AAMA.

AAMA Categories

Based on the determination of the AAMA, powder coatings will be categorized as one of the following:

  • 2630 Specification

Given to basic powder coating types, it identifies materials ideal for coating building interiors like tiles or window sills.  These types of powder coatings will not be able to take the punishment of the outdoors for any substantial amount of time.  However, it can protect significantly better than paint against wear and tear brought about by scuff marks.

The 2603 rating identifies powder coatings with a color retention that will not last over a significantly long time.  On the average, the color of the coating would begin to fade after a year of the application.  The gloss retention is insignificant and has a minimum thickness of 0.8mm.  Powder coatings with 2603 rating can withstand at least 1,500 hours of humidity and salt spray abuse before any noticeable damage can be observed.

  • 2604 Specification

Powder coats in this category are considered as intermediary level and are considered best for high traffic area applications because of its durability.  Color retention is quite acceptable with expectations of about 5 years before fading can be exhibited.

There is a projected 30% loss in the gloss of coats in this category after 5 years of application.  The minimum thickness that can be observed is about 1.2mm.  According to the accelerated testing conducted by the AAMA, coats in this category should be able to withstand abuse from salt spray and humidity for at least 3,000 hours before any damage can occur.

  • 2605 Specification

Considered as the highest rating by the AAMA, powder coats falling under this category can be expected to be extremely tough.  The ability of this coat to withstand harsh outdoor conditions for a significantly long time makes it ideal for applications like huge buildings or stadiums.

To fall under this category, the powder coat should have a color retention of at least 10 years with about 50% gloss retention that should be maintained for 10 years at the very least.  The average thickness should be around 1.2mm.  Powder coatings with 2605 rating must be able to stand up to at least 4,000 hours of salt spray and humidity before any substantial damage should happen.

Contact Byers Bush, a professional powder coating company with AAMA approved applicator today to make sure that you are getting the right powder coating application and help you decide what to use for your specific needs.

Comments are closed.