MIL-HDBK-1110
control agents when cleaning steel. These agents should only be
used in accordance with the contract specification and the
coating manufacturer's recommendations. As for abrasive
blasting, hoses should be in good condition and kept as short as
possible. Special safety precautions, similar to those used in
abrasive-blast cleaning, also need to be taken. In addition,
consideration should be given to the slipperiness of wet
surfaces. More information on safety is provided in Section 13.
9.6.7.3
Frequency of Inspecting Cleaned Surfaces. The
objective of the inspection is to ensure that the entire surface
was prepared in accordance with the specification. The
inspection report should provide a representative description of
the cleaned surface. The specific number and location of places
at which surfaces should be inspected must be in accordance with
the contract specification. If not detailed in the
specification, SSPC PA 2 can be used as a guide. Additional
inspection sites that should be considered include those where
the existing paint was failing, in hard-to-reach areas where
surface preparation is difficult, and where major changes in
equipment were made.
9.6.7.4
Inspecting Prepared Steel Surfaces
a) Cleanliness. If a small representative sample of
surface was not prepared to use as the standard for surface
preparation, the degree of blast or tool cleaning should be
compared to the description given in the SSPC or NACE
specification referred to in the contract specification. The
appearance should correspond with the specified pictorial
standards of SSPC VIS 1, SSPC VIS 3, or a NACE panel. Complete
descriptions of the degrees of cleanliness are found in Section
6. After blasting, blast-cleaned surfaces must be cleaned (e.g.,
vacuum, air blast, or brushing) to remove traces of blast
products from the surface or pitted areas. One of two tests for
cleanliness can be used. In one, a white glove or other clean
cloth is rubbed over the surface and examined for soiling or
debris, and in the other, a piece of clear adhesive tape is
applied to the surface, removed and the adhesive side examined
for debris.
b) Profile. Profile is measured using one of three
pieces of equipment: comparator, depth micrometer, or replica
tape. It should be noted that the three techniques may give
slightly different results. Complete descriptions of standard
methods for each of these techniques are described in ASTM D
4417, Field Measurement of Surface Profile of Blast Cleaned Steel
and in Section 10.
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