What is the minimum cleanliness requirement for SSPC SP-12?

The minimum cleanliness requirement for SSPC SP-12 involves surface preparation that is critical for ensuring effective adhesion of paint systems. SSPC SP-12 specifically pertains to the cleaning of surfaces to remove contaminants in preparation for coating applications.

The correct answer relates to SSPC-WJ 2L and SSPC-WJ 2M, which are guidelines focused on specific levels of cleanliness for steel surfaces. Levels 2L and 2M indicate a defined standard of cleanliness that includes the removal of rust, mill scale, and other contaminants. This ensures that the surface is appropriately prepared prior to the application of coatings, which is essential for promoting adhesion and preventing premature failure of the paint system.

Other options reference different cleanliness levels that do not align with the minimum requirements specified in SSPC SP-12. These standards set various thresholds for cleanliness that may not suffice for the requirements under SP-12, emphasizing the necessary adherence to SSPC-WJ 2L or SSPC-WJ 2M to achieve the proper surface condition before coating. Understanding these standards is crucial for anyone involved in surface preparation and coating application processes in maritime and industrial contexts.