SA 2 1/2 is defined as what level of cleaning?

SA 2 1/2, also known as "Very Thorough Blast Cleaning," is a standardized level of surface preparation according to the Swedish Standard for steel surface cleanliness prior to coatings application. This level indicates that the surface has undergone cleaning to a point where it is nearly free from all visible dirt, dust, rust, scale, and other contaminants.

During the SA 2 1/2 preparation process, the surface should be treated significantly to achieve a roughened texture that enhances the adhesion of coatings. It requires the removal of all loose material and contaminants, ensuring a sound substrate for subsequent paint application. The focus on being "very thorough" highlights the importance of achieving a high level of cleanliness and surface profile, which is essential for optimal coating performance and longevity.

The attributes of this level of cleaning are critical in the coating process as they directly impact the adhesion properties and overall success of the coating application. Understanding the significance of SA 2 1/2 within the context of these standards is essential for anyone involved in surface preparation and coatings application.