Metal finishing Q&As since 1989
-----
AAMA 612 spec for aluminum anodizing
Q. I have recently been searching for a type II clear finish for architectural purposes that can achieve a resiliency equivalent to a AAMA 2605 powder coating or can be warrantied for up to ten years by an applicator. I realize the difficulty involved with this request, however in my searches I came across an AAMA 612 spec for clear anodizing that outlines a 4000-hour salt spray test with only a blister rating of 8 (3% of exposed area experiencing blistering).
Unfortunately I am having difficulty finding a commercial applicator that provides this level of finish. From the data I received from AAMA however, it sounds like this spec is relatively new and was developed primarily in reference to a new type of finishing consisting of a 10-15 micron anodic thickness topped with a 10-15 micron organic sealant or thermosetting resin. I was wondering if anyone is able to provide information on what type of sealant/resin this could possibly be or if there are other clear hybrid-coatings out there that can perform like this.
Jason Traskapplications engineer - St. Paul, Minnesota
2007
A. If you talk to a major supplier of architectural aluminum who offers both anodizing and powder coating, like Southern Aluminum Finishing, they can probably help sort this out for you, Jason.
It is important to remember in a case like this though, that salt spray testing is a QA measure that is to be used to make sure a process hasn't gone south; it does not predicting the durability of one finish vs. another because when you try to accelerate corrosion you change its essence. Some finishes look far better and others look far worse in accelerated salt spray than the real-life situation. If you just go by salt spray hours, you may think you are picking the most durable finish when you are not.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007
"aluminum Structures: Guide to Specifications & Design"
by Kissell & Ferry
on
AbeBooks
or
Amazon
(affil links)
A. Architectural aluminum products produced in accordance with AAMA 612 are superior to other anodic finishes due to their ability to resist corrosion due to mortar contact and salt spray. This finish also resists staining that can be associated with acid rain.
The AAMA 612 standard is the newest anodic finish standard published by the American Architectural Manufacturers Association. It was developed to cover technological advances in anodic finishing processes.
- Austell, Georgia
August 3, 2009
Q, A, or Comment on THIS thread -or- Start a NEW Thread