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Film Loss from Weathering

I have been recently asked how much film loss, in microns or mils, typically occurs per year when a Bis phenol A epoxy powder coating cured with dicydiamide is subjected to South Florida or accelerated UV/weathering exposure.

Charles Danick
Eastman Chemical - Niceville, Florida, USA
2001

Dear Charles,

There is no definite answer to your question. There are so many factors that will affect how long the epoxy takes to degrade, such as formulation, type of epoxy and color. The major disadvantage of an epoxy powder coating no matter how it is cured is there tendency to lose gloss (i.e. chalking) however so far as corrosion protection is concerned, the film loss from chalking is not sufficient to cause a problem under normal conditions. Saying this I would not recommend this type of powder coating for out door use.

Hope this helps,

Drew Devlin
- Lincolnshire
2001