After blasting it is important to assess the cleanliness of the steel. Most high performance coating systems require the steel to be cleaned to a recognised standard. Recognised standards include S.S.P.C. (Steel Structures Painting Council USA), N.A.C.E. (National Association of Corrosion Engineers), SA (Swedish Standards Organisation).
Contamination
The presence of contamination in the form of chlorides, sulphates and nitrates (commonly known as salt ions) prior to the coating being applied can lead to premature coating failure in the form of delamination and blistering.
These salt ions can be present on the surface to be coated due to a number of reasons: locations off-shore or shore side are obviously susceptible to salt contamination from the sea, salt can be present in water used to wash down the surface, salt can be present in new or recycled abrasives used to blast the surface. Once the presence of salt has been detected it can be cleaned and controlled reducing the risk of premature coating failure.
AIE - The Guide breaks down the inspection process into six distinct steps. Each stage in the process of surface treatment is critical in guarding against premature coating failure.
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