What does SA-3 refer to in cleaning methods?

SA-3 refers to "Blast Cleaning to Visually Clean Steel," which indicates a specific level of cleanliness achieved through abrasive blasting methods, typically using materials such as sand or steel shot. This designation comes from the SSPC (Society for Protective Coatings) and is part of the surface preparation standards used in preparing metal substrates prior to coating application.

When a surface is prepared to the SA-3 standard, it means that the cleaning method has successfully removed all rust, mill scale, and old coatings, leaving a surface that is visibly clean and free from contaminants. This level of cleaning ensures that the new coating adheres properly and performs effectively over its service life, reducing the risk of failure due to poor adhesion or corrosion.

Understanding this cleanliness standard is crucial for inspectors and contractors in the coatings industry, as it helps ensure that surfaces are adequately prepared before the application of protective coatings, thus contributing to the longevity and durability of the coating systems used.