What is the definition of SA 2 in the context of blast cleaning?

The definition of SA 2 in the context of blast cleaning refers to "Thorough Blast Cleaning." This term indicates a specific level of cleanliness achieved through surface preparation using abrasive blasting techniques. At this level, all visible rust, mill scale, and old coatings should be removed, leaving a surface that is clean and uniform, free from contaminants that could adversely affect the performance of subsequent coating applications.

The use of the term "thorough" emphasizes the requirement that the majority of the surface must be prepared adequately to ensure good adhesion of the applied coatings. It's essential for the success of coating systems to have a surface that meets this cleanliness standard because any remaining contaminants can lead to coating failures such as peeling, blistering, or corrosion under the coating film.

Options suggesting "Light Blast Cleaning," "Very Thorough Blast Cleaning," or "Power Tool Cleaning" refer to different levels or methods of surface preparation that do not accurately characterize the specific criteria of SA 2, which focuses distinctly on achieving a thorough cleanliness standard.