Surface Preparation

VariBlast uses a wide range of surface preparation methods and techniques to ensure the highest standard of finish at all times

Steel Preparation Finishes

The key to a good, long lasting finish is in the standard and quality of the surface preparation. Prior to applying any coating we ensure that our highly skilled operators prepare the surface to match or exceed the specified standard.

The following is a comprehensive list of the standards of finish we can achieve on steel

National Association of Corrosion Engineers (NACE)

  • NACE 1 White Metal Blast Cleaning
  • NACE 2 Near-White Blast Cleaning
  • NACE 3 Commercial Blast Cleaning

 

Steel Structures Painting Council (SSPC)

  • SP-1 Solvent Cleaning
  • SP-2 Hand Tool Cleaning
  • SP-3 Power Tool Cleaning
  • SP-4 Flame Cleaning
  • SP-5 White Metal Blast Cleaning
  • SP-6 Commercial Blast Cleaning
  • SP-7 Brush-Off Blast Cleaning
  • SP-8 Pickling
  • SP-9 Weathering Followed By Blast Cleaning
  • SP-10 Near-White Blast Cleaning

 

Swedish Standard (St,Sa)

  • St 2 Hand Tool Cleaning
  • St 3 Power Tool Cleaning
  • Sa 1 Brush-Off Blast Cleaning
  • Sa 2 Commercial Blast Cleaning
  • Sa 2 ½ Near-White Blast Cleaning
  • Sa 3 White Metal Blast Cleaning

 

SSPC-SP-1
Solvent Cleaning
Removal of all detrimental foreign matter such as oil, grease, dirt, soil, salts, drawing and cutting compounds, and other contaminants from steel surfaces by the use of solvents, emulsions, cleaning compounds, steam or other similar materials and methods which involve a solvent or cleaning action.

SSPC-SP-2/St 2
Hand Tool Cleaning
Removal of all rust scale, mill scale, loose rust and loose paint to the degree specified by hand wire brushing, hand sanding, hand scraping, hand chipping or other hand impact tods or by a combination of these methods. The substrate should have a faint metallic sheen and also be free of oil, grease, dust, soil, salts and other contaminants.

SSPC-SP-3/St 3
Power Tool Cleaning
Removal of all rust scale, mill scale, loose paint, and loose rust to the degree specified by power wire brushes, power impact tools, power grinders, power sanders or by a combination of these methods. The substrate should have a pronounced metallic sheen and also be free of oil, grease, dirt, soil, salts and other contaminants. Surface should not be buffed or polished smooth.

SSPC-SP-4
Flame Cleaning
Removal of all loose scale, rust and other detrimental foreign matter by passing high temperature, high velocity oxy-acetylene flames over the entire surface, followed by wire brushing. Surface should also be free of oil, grease, dirt, soil, salts and other contaminants.

SSPC-SP-5/Sa3/NACE 1
White Metal Blast Cleaning
Removal of all mill scale, rust, rust scale, paint or foreign matter by the use of abrasives propelled through nozzles or by centrifugal wheels. A White Metal Blast Cleaned Surface Finish is defined as a surface with a gray-white, uniform metallic color, slightly roughened to form a suitable anchor pattern for coatings. The surface, when viewed without magnification, shall be free of all oil, grease, dirt, visible mill scale, rust, corrosion products, oxides, paint, or any other foreign matter.

SSPC-SP6/Sa2/NACE 3
Commercial Blast Cleaning
Removal of mill scale, rust, rust scale, paint or foreign matter by the use of abrasives propelled through nozzles or by centrifugal wheels, to the degree specified. A Commercial Blast Cleaned Surface Finish is defined as one from which all oil, grease, dirt, rust scale and foreign matter have been completely removed from the surface and all rust, mill scale and old paint have been completely removed except for slight shadows, streaks, or discolorations caused by rust stain, mill scale oxides or slight, tight residues of paint or coating that may remain; if the surface is pitted, slight residues of rust or paint may by found in the bottom of pits; at least two-thirds of each square inch of surface area shall be free of all visible residues and the remainder shall be limited to the light discoloration, slight staining or tight residues mentioned above.

SSPC-SP-7/Sa1
Brush-Off Blast Cleaning
Removal of loose mill scale, loose rust, and loose paint, to the degree hereafter specified, by the impact of abrasives propelled through nozzles or by centrifugal wheels. It is not intended that the surface shall be free of all mill scale, rust, and paint. The remaining mill scale, rust, and paint should be tight and the surface should be sufficiently abraded to provide good adhesion and bonding of paint. A Brush-Off Blast Cleaned Surface Finish is defined as one from which all oil, grease, dirt, rust scale, loose mill scale, loose rust and loose paint or coatings are removed completely but tight mill scale and tightly adhered rust, paint and coatings are permitted to remain provided that all mill scale and rust have been exposed to the abrasive blast pattern sufficiently to expose numerous flecks of the underlying metal fairly uniformly distributed over the entire surface.

SSPC-SP-8
Pickling
Removal of all mill scale, rust and rust scale by chemical reaction, or by electrolysis, or by both. It is intended that the pickled surface shall be completely free of all scale, rust, and foreign matter. Furthermore, the surface shall be free of unreacted or harmful acid or alkali, or smut.

SSPC-SP-9
Weathering Followed By Blast Cleaning
Weathering to remove all or part of the mill scale followed by one of the blast cleaning standards.

SSPC-SP-10/Sa 2-½/NACE 2
Near-White Blast Cleaning
Removal of nearly all mill scale, rust, rust scale, paint, or foreign matter by the use of abrasives propelled through nozzles or by centrifugal wheels, to the degree hereafter specified. A Near-White Blast Cleaned Surface Finish is defined as one from which all oil, grease, dirt, mill scale, rust, corrosion products, oxides, paint or other foreign matter have been completely removed from the surface except for very light shadows, very slight streaks or slight discolorations caused by rust stain, mill scale oxides, or light, tight residues of paint or coating that may remain. At least 95 percent of each square inch of surface area shall be free of all visible residues, and the remainder shall be limited to the light discoloration mentioned above.

Please note:
Other preparation grades and specifications are also recognised by VariBlast within the blasting, painting and preparation industry. If they are not already listed above please contact us directly to discuss your requirements .

Surface Preparation Case Studies

Bullring Centre, Birmingham

MOD Pendine Firing Range

RAF Mildenhall

Middleton Stop Pump

Kensington Olympia

Herbal House

Happisburgh Lighthouse

Eye Power Station

Southbank Centre

148 Old Street

Halterman Carless

International Aviation Academy

To arrange a site meeting or discuss a quote, call VariBlast now on 01508 493320 or email info@variblast.com