As part of the normal ageing process, galvanized surfaces form an outer layer of oxide. This protects the reactive zinc and underlying steel from further corrosion. The appearance of the surface ranges from bright silver to dull grey. Exposure to road salt can change the appearance of newly galvanized surfaces to dull grey or black with white or grey deposits. This does not affect the protective properties of the finish.
To minimize this effect, new trailers should be washed regularly to remove any accumulated grime and road salt. This will become less important after the first few months as the protective layer forms on the surface. However, we would still recommend regular washing.