MIL-HDBK-1110
6.4.2
Nonferrous Unpainted Substrates. There are no
standards describing the condition of other building material
substrates.
6.5
Standards for Cleanliness of Substrates
6.5.1
Standards for Cleaned Steel Surfaces
6.5.1.1
SSPC and NACE Definitions and Standards. The SSPC and
the NACE Standards are used most frequently for specifying degree
of cleanliness of steel surfaces. SSPC has standard definitions
and photographs for common methods of cleaning (SSPC VIS 1 and
SSPC VIS 3, Power- and Hand-Tool Cleaned Steel). NACE TM0170,
Surfaces of New Steel Air Blast Cleaned With Sand Abrasive;
definitions and metal coupons) covers only abrasive blasting.
Volume 2 of SSPC Steel Structures Painting Manual contains all
the SSPC standards, as well as other useful information. For
both types of standards, the definition, rather than the
photograph or coupon, is legally binding. The SSPC and NACE
surface preparation standards are summarized in Table 7.
To use the SSPC or NACE standards, first determine the
condition of steel that is to be blasted (e.g., Grade A, B, C, or
D), since different grades of steel blasted to the same level do
not look the same. After determining the condition of steel,
compare the cleaned steel with the pictorial standards for that
condition. The appearance of blasted steel may also depend upon
the type of abrasive that is used. NACE metal coupons represent
four degrees of cleanliness obtained using one of three types of
abrasives - grit, sand, or shot.
6.5.1.2
Job-Prepared Standard. A job-specific standard can be
prepared by blasting or otherwise cleaning a portion of the
structure to a level acceptable to both contractor and
contracting officer, and covering it with a clear lacquer
material to protect it for the duration of the blasting. A
12-inch steel test plate can also be cleaned to an acceptable
level and sealed in a water- and grease-proof bag or wrapper
conforming to MIL-B-131, Barrier Materials, Water Vaporproof,
Greaseproof, Flexible, Heat-Sealable.
6.5.1.3
Pictorial Standards for Previously Painted Steel.
Photographic standards for painted steel are available in the
Society for Naval Architects and Engineers Abrasive Blasting
Guide for Aged or Coated Steel Surfaces. Pictures representing
paint in an original condition and after each degree of blasting
are included.
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