Salt spray testing keeps a check on corrosion

Equipment required for the salt spray chamber comprises the holding tank with its salt solution of between 4-6% pH and the salt spray cabinet itself where the salt water solution is atomised using pressurised air. The samples to be tested are then exposed to this extremely corrosive saline fog for the requisite amount of time, which can be days or weeks depending on the standard to be achieved. Regular daily tests ensure that temperature and the specific gravity of the salt solution are maintained at a level consistent with ASTM B117, an internationally recognised salt spray standard.

The salt spray test is generally applied to items coated in, for example, Delta-tone or KTL-Black. These coatings, used in the aerospace and automotive industries, typically are required to meet specifications which include a number of hours of salt spray testing. The requirements that William Hughes meet range from 48 hours to over 600 hours of salt spray testing.