The test standard summaries are for general guidance only. Though believed to be accurate at the time of writing, this may change over time. So this information should not be used as a substitute for referring to a complete test standard, at an appropriate revision level.
Note: the terms salt spray, salt mist and salt fog are all in wide spread use within corrosion test standards. In this context they can be considered to be equivalent and interchangeable terms.
NFT 30-077
Kesternich testing simulates acid rain or industrial chemical exposure to evaluate the relative corrosion resistance of the coating, substrate, or part itself. Parts or panels are placed inside a specially designed chamber and are exposed to SO2 and humidity before being evaluated for resistance to corrosion. The following standard used in this type of test.
NFT 30-077 Test Standard specifies a method for determining the resistance of a paint film, paint systems and related products to conditions of high humidity. The method is applicable to coatings both on porous substrates, such as wood, plaster and plasterboard, as well as on non-porous substrates, such as metal. It gives an indication of the performance likely to be obtained under severe exposure conditions and when continuous condensation occurs on the surface. The procedure may show coating defects (including blistering, staining, softening, crimping, embrittlement) and deterioration of the substrate. It also determines Ash Content.