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Grey Galvanized Steel – The “Grey Bar Effect”

Why does my galvanizing look Dull grey?

This out come is what we refer to as a ‘grey bar’ where the steel chemistry influences the metallurgic reaction that is galvanizing. The levels of phosphorous or silicon plus other elements in the steel can increase the iron content on the “eta” (top) layer resulting in a dull finish. This in no way is inferior or affects the performance of the coating, it just looks different as the photo’s depict. The spliced piece clearly shows the difference in steel chemistry reaction as obviously this member was immersed for the same time in each of the process tanks. This can be critical in architectual applications where asthetic’s are considered. Note while the ‘grey bar’ effect is dull it does accelerate the reaction resulting in almost double coating thickness.

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