SSPC-VIS 4/NACE VIS 7 – Guide and Reference Photographs for Steel Surfaces Prepared by Waterjetting

SSPC-VIS 4/NACE VIS 7 – Guide and Reference Photographs for Steel Surfaces Prepared by Waterjetting

SSPC VIS4 / NACE VIS 7 – Guide and Reference Photographs for Steel Surfaces Prepared by Waterjetting. Shows previously coated and uncoated, rusted steel surfaces cleaned to WJ 1, WJ 2, WJ 3, and WJ 4 finishes as defined by the SSPC/NACE standard for waterjetting (SP 12/NACE 5). Additional photos illustrate degrees of light, moderate, and heavy flash rusting after waterjetting. The standard applies to surface preparation by high pressure water cleaning for a paint coating. It distinguishes three levels of cleanliness with reference to visible contaminants (Wa 1 – Wa 2½) such as rust, mill scale, old paint coatings and other foreign matter. Wa 1 : Light high-pressure water jetting When viewed without magnification, the surface shall be free from visible oil and grease, loose or defective paint, loose rust and other foreign matter. Any residual contamination shall be randomly dispersed and firmly adherent. Wa 2 : Thorough high-pressure water jetting When viewed without magnification, the surface shall be free from visible oil, grease and dirt and most of the rust, previous paint coatings and other foreign matter. Any residual contamination shall be randomly dispersed and can consist of firmly adherent coatings, firmly adherent foreign matter and stains of previously existent rust. Wa 2½ : Very thorough high-pressure water jetting When viewed without magnification, the surface shall be free from all visible rust, oil, grease, dirt, previous paint coatings and, except for slight traces, all other foreign matter. Discoloration of the surface can be present where the original coating was not intact. The grey or brown/black discoloration observed on pitted and corroded steel cannot be removed by further water jetting. Elcometer E128-7. TQC Art. No. LD3058. NACE, National Association of Corrosion Engineers.