NACE WJ-2/SSPC-SP WJ-2:2012

Defines the Very Thorough Cleaning (WJ-2) degree of surface cleanliness of coated or uncoated metallic substrates achieved by the use of waterjet cleaning before the application of a protective coating or lining. WJ-2 provides a greater degree of surface cleanliness than Thorough Cleaning (WJ-3), but a lesser degree of surface cleanliness than Cleaning to Bare Substrate (WJ-1). Waterjet cleaning to achieve the WJ-2 degree of surface cleanliness is used when the objective is to remove almost all rust and other corrosion products, coating, and mill scale, but when the extra effort to remove all of these materials is determined to be unwarranted. Discoloration of the surface may be present. Waterjet cleaning is the use of pressurized surface preparation water for removing coatings and other materials, including hazardous materials, from a substrate to achieve a defined degree of surface cleanliness. The four degrees of surface cleanliness achieved by waterjet cleaning are addressed in separate standards as follows: Clean to Bare Substrate (NACE WJ-1/SSPC-SP WJ-1[WJ-1]), Very Thorough Cleaning (NACE WJ-2/SSPC-SP WJ-2 [WJ-2]), Thorough Cleaning (NACE WJ-3/SSPC-SP WJ-3 [WJ-3]), and Light Cleaning (NACE WJ-4/SSPC-SP WJ-4 [WJ-4]).