| Several
organizations provide specifications and standards on surface
preparation. In particular, SSPC-The Society for Protective Coatings
and NACE International provide some very useful specifications
and standards for use in cleaning both steel and concrete surfaces.
Visual standards are available which show the varying levels of
surface cleanliness that can be achieved using methods such as
dry abrasive blasting, hand tool cleaning or ultra-high pressure
waterjetting. A brief description of the specifications are given
below for reference. Click here for an example of how these standards
would be used.
Solvent Cleaning (SSPC-SP 1 )
This specification describes the requirements for solvent cleaning
of steel surfaces. Solvent cleaning is a technique for removal
of visible oil, grease, dirt, and other soluble contaminants.
Solvent cleaning should be used prior to the application of
paint, and in conjunction with other surface preparation methods,
as necessary.
Hand Tool Cleaning
(SSPC-SP 2)
This standard covers requirements for hand tool cleaning of
steel surfaces by the use of non-power hand tools. Hand tool
cleaning removes loose mill scale, loose rust, loose paint and
other loose matter. It is not intended for removal of adherent
mill scale, rust or paint, i.e., mill scale, rust and paint
which can not be removed by lifting with a dull putty knife.
Power Tool Cleaning
(SSPC-SP 3)
This standard covers requirements for power tool cleaning of
steel surfaces by the use of power-assisted hand tools. Power
tool cleaning removes loose mill scale, loose rust, loose paint
and other loose matter. It is not intended for removal of adherent
mill scale, rust or paint, i.e., mill scale, rust and paint
which can not be removed by lifting with a dull putty knife.
White Metal Blast
Cleaning (SSPC-SP 5/ NACE No.1)
This standard covers requirements for white metal blast cleaning
of unpainted and painted steel surfaces by the use of abrasives.
These requirements include the final condition of the surface,
as well as materials and procedures used to achieve and verify
the final condition.
A white metal blast cleaned surface, when viewed without magnification,
is free of all visible oil, grease, dust, dirt, mill scale,
rust, coating, oxides, corrosion products, and other foreign
matter.
Commercial Blast Cleaning
(SSPC-SP 6/ NACE No.3)
This standard covers requirements for commercial blast cleaning
of unpainted and painted steel surfaces by the use of abrasives.
These requirements include the final condition of the surface,
as well as materials and procedures used to achieve and verify
the final condition.
A commercial blast cleaned surface, when viewed without magnification,
is free of all visible oil, grease, dust, dirt, mill scale,
rust, coating, oxides, corrosion products, and other foreign
matter, except for staining as noted in the standard. Staining
is limited to no more than 33 percent of each square inch of
surface area, and may consist of light shadows, slight streaks,
or minor discolorations caused by stains of rust, stains of
mill scale, or stains of previously applied coatings.
Brush Off Blast Cleaning
(SSPC-SP 7/ NACE No. 4)
This standard covers requirements for brush-off blast cleaning
of unpainted and painted steel surfaces by the use of abrasives.
These requirements include the final condition of the surface,
as well as materials and procedures used to achieve and verify
the final condition. A brush-off blast cleaned surface, when
viewed without magnification, is free of all visible oil, grease,
dirt, dust, loose mill scale, loose rust, and loose coating.
Tightly adherent mill scale, rust, and coating may remain on
the surface.
Near-White Blast Cleaning
(SSPC-SP 10/ NACE No.2)
This standard covers requirements for near white blast cleaning
of unpainted and painted steel surfaces by the use of abrasives.
These requirements include the final condition of the surface,
as well as materials and procedures used to achieve and verify
the final condition. A near-white blast cleaned surface, when
viewed without magnification, is free of all visible oil, grease,
dust, dirt, mill scale, rust, coating, oxides, corrosion products,
and other foreign matter, except for staining as noted in the
standard. Staining is limited to no more than 5 percent of each
square inch of surface area, and may consist of light shadows,
slight streaks, or minor discolorations caused by stains of
rust, stains of mill scale, or stains of previously applied
coatings.
Power Tool Cleaning
to Bare Metal (SSPC-SP 11)
This standard covers the requirements for power tool cleaning
to produce a bare metal surface and to retain or produce a minimum
surface profile of 1 mil. This standard is suitable where a
roughened, clean, bare metal surface is required, but where
abrasive blasting is not feasible or permissible.
It differs from SSPC-SP 3, Power Tool Cleaning, in that SSPC-SP
3 requires only the removal of loosely adhered materials, and
does not require producing or retaining a surface profile.
Surface Preparation
and Cleaning of Metals by Waterjetting Prior to Recoating (SSPC-SP
12/ NACE No.5)
This standard covers the use of high- and ultra-high pressure
waterjetting to achieve defined degrees of cleanliness on metal
surfaces, primarily carbon steel, and is limited in scope to
only the use of water. The requirements include the final condition
of the surface, as well as materials and procedures used to
achieve and verify the final condition.
Surface Preparation
of Concrete (SSPC-SP 13/ NACE No.6)
This standard covers requirements for the preparation of concrete
surfaces by mechanical, chemical, or thermal methods. The requirements
of this standard are applicable to all types of cementitious
surfaces including cast-in-place concrete floors and walls,
precast slabs, masonry walls, and shotcrete surfaces. An acceptable
prepared concrete surface should be free of contaminants, laitance,
loosely adhering concrete, and dust. A sound, uniform substrate
should be available for the application of coatings.
Industrial Blast Cleaning
(SSPC-SP 14/ NACE No.8)
This standard covers requirements for industrial blast cleaning
of unpainted and painted steel surfaces by the use of abrasives.
These requirements include the final condition of the surface,
as well as materials and procedures used to achieve and verify
the final condition. An industrial blast cleaned surface, when
viewed without magnification, is free of all visible oil, grease,
dirt, and dust. Traces of tightly adherent mill scale, rust,
and coating may remain on 10 percent of each square inch of
the surface if evenly distributed. Shadows, streaks, and discolorations
caused by stains of rust, stains of mill scale, and stains of
previously applied coating may be present on the remainder of
the surface.
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