SSPC SP 7
Brush-off Blast Cleaning
|Publication Date:||1 September 2000|
This joint standard covers the use of blast cleaning abrasives to achieve a defined degree of cleaning of steel surfaces prior to the application of a protective coating or lining system. This standard is intended for use by coating or lining specifiers, applicators, inspectors, or others whose responsibility it may be to define a standard degree of surface cleanliness.
The focus of this standard is brush-off blast cleaning. White metal blast cleaning, near-white blast cleaning, commercial blast cleaning, and industrial blast cleaning are addressed in separate standards.
Brush-off blast cleaning provides a lesser degree of cleaning than industrial blast cleaning (SSPC-SP 14/NACE No. 8). The difference between an industrial blast and a brush-off blast is that the objective of a brush-off blast is to allow as much of an existing coating to remain as possible, and to roughen the surface prior to coating application while the purpose of the industrial blast is to remove most of the coating, mill scale and rust, when the extra effort required to remove every trace of these is determined to be unwarranted.
This joint standard was prepared by the SSPC/NACE Task Group A on Surface Preparation by Abrasive Blast Cleaning. This joint Task Group includes members of both the SSPC Surface Preparation Committee and the NACE Unit Committee T-6G on Surface Preparation (now STG 04).