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Salt spray correlation

We are doing some salt spray testing on aluminum fishing reels. Does anyone know of a correlation between salt spray hours and real life service?

Vic Waldman
- Naugatuck, Connecticut
 

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Hi, Vic. A well anodized surface will last longer in a salt spray cabinet, and in the real world, than a poorly anodized surface. Unfortunately that's the end of the correlation :-)

The corrosion mechanism is different and the reactions are different. For example, in the real world galvanized coatings build zinc carbonate reaction products by slowly reacting over time with the carbon dioxide in the air. These adherent and resistant corrosion products help galvanizing last for 50 to 60 years severe exposure in the real world; other coatings can't touch it. But in a salt spray cabinet where the carbonates have no opportunity to form, galvanized coatings perform poorly.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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Hi Vic,

No correlation exists between salt spray performance and real-life service.

George Gorecki
- Naperville, Illinois
 

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I have always said that salt fog testing is too widely used and abused. I say this because, the environment within the salt fog chamber is salt. Unless your product will see real world environments such as the salt chamber, there would not be any correlation. Further, aluminum generally is not put into a salt fog chamber, because it would take a very long time to destroy the integrity of the topcoat on an aluminum surface. I believe that many times, companies do not use powders thats may have failed in the salt fog arena, but certainly would pass many more hours of regular moisture. A better idea would be to ask your test experts to use a cyclic chamber instead of the typical salt fog chamber. I believe the cyclic chambers will become more prevalent in the future for this very reason.

Bob Utech
Benson, Minnesota