Salt Fog testing is a popular method to provide accelerated corrosion test conditions, which is important for evaluating the resistance of marine, automobile, and aircraft coatings and any other exterior coating exposed to salt spray by being near the ocean or exposed to salted road conditions. The test determines the suitability of a coating for use as a protective finish by producing a corrosive attack to coated specimens and the appearance of corrosion products is evaluated after a pre-determined period of time. The test requires a salt fog cabinet as shown in the Figure below and coated panels. The test coatings will be scored to the bare substrate as per the test requirement and the edges of the test panels will be sealed with a weatherproof tape. The panels will be placed in the cabinet and exposed to the settling fog of an atomized neutral (pH 6.5 to 7.2) 5% NaCl solution for a specified period of time. The sample will be periodically checked to see if the rusted exposed metal has propagated under the coating causing coating failure.
Test methods for the Salt Spray are available in:
- ASTM B117
- ASTM G85
- ISO 9227
All-side coated steel panels or external coated parts