AAMA Coastal Committee Studies Corrosion

The American Architectural Manufacturers Association (AAMA) Costal Coating Subcommittee, which first formed in May, discussed corrosion in coastal applications recently at the association's fall meeting last week in Florida. The group's mission is to develop a stand-alone, higher-performing specification for seacoast locations that applies to all three existing coating specifications (AAMA 2603, 2604 and 2605) and contains additional performance tests to simulate exposure in seacoast environments.

"Our intent here was to try to move the ball," said Valspar's Chick Newhouse, committee chair. This is an enormous issue and people aren't paying attention to it. Hopefully this will give it some attention."

Newhouse reported results of some tests conducted since the May meeting and much of the time was spent having committee members look at the test panels. The group is focusing on three accelerated tests: CASS (1,000 hours), MACHU and Filiform.

"We thought we would see spectacular failure in two-coat products but we didn't get that," he said. "Why corrosion went all the way through the panel we don't know."

All test panels were treated in the lab then painted together in an industrial setting.

The results showed no attack on the extrusion regardless of the paint system, and the group reported that the roll-formed product performed much worse than extrusion. The committee discussed that perhaps the MACHU test wasn't severe enough for the extrusion, and that the committee might want to look into a more severe test.

The committee must still determine how much corrosion will be considered acceptable.

"We're trying to find a test for these coastal properties," said David Calabra of Sherwin Williams. "It's challenge finding a test that is going to tell us that a product will last ten years. Even if it passes 1,000 or 1,500 hours, will it pass ten years?"

"That's the big question to answer-correlation [of these tests] to the real world," added Newhouse.

He then addressed the fact that some companies will choose to offer products that do not meet this new specification.

"Yes, it will be expensive. Yes, there will be environmental considerations. Yes, there will be changes that have to be made," he said.

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