[L1] 1 Surface Pre-treatment [L2] 1) Definition and Purpose [L4] - To obtain a high-quality coating film, the degree of adhesion of the coating film must be good, and for this, surface roughness matching the paint is required. The pre-treatment to create appropriate surface roughness is called surface pre-treatment. [L5] * Surface roughness must be specified separately from the surface treatment item in the painting specification. [L2] 2) Pre-treatment Criteria [L4] - Surface treatment must be done to the extent required by the paint to be used. [L4] - If there is no drawing or special mention, it is appropriate to treat to the level of 25~27㎛. [L4] - Generally, abrasive cleaning is required based on SSPC standard SP10 or equivalent. [L2] 3) Surface Treatment Method and Painting Procedure [L4] - All objects to be painted must undergo surface treatment to the extent required by the paint. [L4] - Blast cleaning is performed after removing contaminants from the object. [L4] - After blast cleaning, residual foreign substances must be removed with a brush or compressed air. [L4] - Painting must be done within 3 hours after blast cleaning, and blast cleaning is performed again upon re-rusting. [L4] - Must be treated above the standard specified in the painting specification. [L1] 2 Grades of Surface Treatment [L2] 1) Cleaning and Conditioning Grades (SSPC Grades) [L2] 2) Details of Cleaning and Conditioning Grades [L3] ① Solvent Cleaning (SSPC-SP1) [L4] - Removal of oil, dust, and contaminants by cleaning with solvents, vapor, alkali, and emulsions. [L3] ② Power Tool Cleaning (SSPC-SP3) [L4] - Method of surface treatment with scraping and wire brushing. [L4] - Since it may be vulnerable to rusting and contamination, painting treatment must proceed within 3 hours after processing. [L3] ③ White Metal Blast Cleaning (SSPC-SP5) [L4] - Refers to blast cleaning by nozzle using sand, grit, and shot. [L4] - State where all oil, mill scale, rust, and foreign substances attached to the metal surface are completely removed. [L4] - Must show the color of the original metal. [L3] ④ Brush-Off Blast Cleaning (SSPC-SP7) [L4] - Cleaning more than 2/3 of the surface area of all visible rust, mill scale, coating film, and other foreign substances. [L3] ⑤ Near-White Metal Blast Cleaning (SSPC-SP10) [L4] - State where all oil, mill scale, rust, and foreign substances attached to the metal surface are almost completely (95%) removed. [L4] - Minute stains or discoloration may exist, but it must show the color of the original metal.