Are salt spray tests reliable in determining the lifespan of a hot dip galvanized coating?

For years salt spray tests have been used to approximate environments where galvanized material will be utilized. For equally as long, they have been criticized for their inability to accurately duplicate specific environments. A salt spray test bombards the immature zinc coating with a very aggressive element (salt). It attacks the most outer layer, referred to as the patina. Patina develops on galvanized material several months after galvanizing. Therefore, subjecting zinc to an aggressive environment prior to it maturing and forming its patina completely can often lead to results revealing a much shorter lifespan than would naturally be found.  more