Surface Cleaning Standards
There are four main standards of blast cleaning steel surfaces which include, Brush Off, Commercial, Near white metal, & White metal, with each reaching a different level of surface cleaning, & all standards commanding a different price.
Brush Off – S.A.1 (Swedish standards)
Brush Off blast cleaning is a standard of surface preparation, which when viewed without magnification is free of all visible oil, grease, dirt, dust, loose mill scale, loose rust, & old paint/coatings.
Tightly adherent mill scale, rust & old paint/coatings may remain on the surface. Mill scale, rust & paint/coatings are considered adherent if they cannot be removed by lifting with a dull putty knife.
Other recognised Brush Off standards include:
SSPC-SP7 – (SSPC The society for protective coatings USA).
NACE No.4 – (National association of corrosion engineers USA)
Commercial – S.A. 2 (Swedish standards)
Commercial blast cleaning is a method of preparing steel surfaces which, when viewed without magnification, shall be free of all visible oil, grease, dirt, dust, mill scale, rust & paint/coatings. Generally evenly dispersed very light shadows, streaks & discolorations caused by stains of rust, mill scale or previously applied paint/coatings may remain on more than 33% of the surface.
Other recognised commercial standards include:
SSPC-SP6 – (SSPC The society for protective coatings USA).
NACE No.3 – (National association of corrosion engineers USA)
3RD QUALITY – (United Kingdom standards BS 4232)
Near White Metal – S.A. 2.5 (Swedish standards)
Near white metal blast cleaning is a method of preparing steel surfaces which, when viewed without magnification, shall be free of all visible oil, grease, dirt, dust, mill scale & paint/coatings. Generally evenly dispersed very light shadows, streaks & discolorations caused by stains of rust, mill scale or previously applied paint/coatings may remain on no more than 5% of the surface.
Other recognised near white metal standards include:
SSPC-SP10 – (SSPC The society for protective coatings USA).
NACE No.2 – (National association of corrosion engineers USA)
2ND QUALITY – (United Kingdom standards BS 4232)
White Metal – S.A. 3 (Swedish standards)
White metal blast cleaning is a method of preparing steel surfaces which, when viewed without magnification, shall be free of all visible oil, grease, dirt, dust, mill scale, rust & paint/coatings.
Other recognised white metal standards include:
SSPC-SP5 – (SSPC The society for protective coatings USA).
NACE No.1 – (National association of corrosion engineers USA)
1ST QUALITY – (United Kingdom standards BS 4232)