MIL-DTL-53072E
d. Method IV
Emulsion cleaning, with or without added water.
e. Method V
Derusting by chemical means.
f. Method VI
Phosphoric acid cleaner (detergent or solvent type with detergent)
g. Method VII
Steam cleaning, with or without assisted pressure washing.
After cleaning, all surfaces shall be kept free from dirt, dust, finger marks, and other
contaminants until treated as specified. If the CARC system cannot be applied immediately after
cleaning, then the parts shall be protected from flash rusting and from contamination. Prior to
applying the CARC system, the parts shall be re-inspected and cleaned, as required, and pass the
water break test (see 4.2.3.1.1).
3.2.1 Abrasive blasting of ferrous metal surfaces. Unless otherwise specified, ferrous metal
surfaces to be painted shall be cleaned in accordance with 3.2. If abrasive blasting is used to
remove mill scale, products of corrosion, dirt, casting sand, slag and other foreign substances,
then follow the procedure in the Society for Protective Coatings specification SSPC-SP5/NACE
No. 1 or SSPC-SP10/NACE No. 2, unless otherwise specified. Abrasive blasting shall always be
preceded by cleaning methods most appropriate for the application to assure the substrate is
water-break free clean. Using clean water, for example, distilled, deionized, Reverse Osmosis
(RO) purified or filtered water in an atomizing sprayer works well in this method for determining
the results as described in 4.2.3.1.1. The blast media and maintenance of the abrasive blasting
system shall be such that a consistent surface profile is maintained throughout the process and
subsequent abrasive blast cleaning. Surface profile measurements shall not exceed the
recommended range for the coating system applied and is recommended to be 1.0±0.5 mils,
unless specified by the coating manufacturer so as to maintain the performance for coating
adhesion and corrosion resistance. Ferrous media or media contaminated with ferrous spoils from
previous abrasive blasting shall not be used on non-ferrous metallic substrates. Blast cleaned
surfaces shall be coated within four hours with a suitable wash primer or other approved
pretreatment material. Applied wash primer shall be dried for at least one hour at a preferred
temperature range of 60 to 90 ºF (16 to 32 ºC). If more than four hours pass before pretreatment,
the blasted surface shall be inspected and found free of corrosion or foreign matter, and pass the
water break test (see 4.2.3.1.1) prior to pretreatment and priming. When the use of hexavalent
chromium is restricted by contractual requirements, TT-C-490, type I, qualified pretreatments to
TT-C-490, types III, IV, and VIII, class A or C or zinc-rich primers conforming to A-A-59745
shall be used as the alternatives on blasted ferrous substrates. Approval from the contracting
officer shall be received prior to use of zinc-rich primers on blasted ferrous substrates. The
requirement for primer dry film thickness (see 4.2.3.3) over a blasted profile is based upon film
build over the peaks of the surface profile.
3.2.1.1 Exemptions from abrasive blasting. Abrasive blasting shall not be used on surfaces that
could be damaged, such as machine parts and sheet metal thinner than 16 gauge (0.0625 inches
or 1.5875 mm). Blasting is optional, on components painted for protection during limited
storage, where the paint wears off as soon as the equipment is placed in use. Component
examples are track assemblies, track roller assemblies (including mounting frames), interiors of
weld-type box sections, bulldozer components (including rippers, scarifiers, ejectors, push plates,
blades, bowls, and buckets), scrapers and crane shovels, interiors of cement mixer drums, and
interiors of aggregate driers. However, these surfaces shall be cleaned using one of the methods
described in 3.2 and shall be free from oil, grease, dirt, and rust. All surfaces shall be dry prior to
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