TM 43-0139
f.
Hardware and Hardware Items. Hardware and hardware items such as bolts, capscrews, washers, pins, springs,
and grease fittings are not to be cleaned and treated prior to assembly and painting if there is no evidence of rust or
corrosion.
g.
Corrosion-Resisting Steel Surfaces. Corrosion-resisting steel surfaces shall be cleaned as specified in paragraph
3-3 above, then treated as follows (unless the corrosion-resisting steel has already been passivated and has not been
contaminated or depassivated by working, forming, or shaping the end item). The process specified below is primarily a
passivating treatment for corrosion-resisting steels and is not cleaning treatment.
(1)
Degrease, as in MIL-S-5002.
(2)
Immerse for 30 minutes in a solution containing 20 percent by volume of nitric acid and two percent by
weight of sodium dichromate at 120°F to 1300F.
(3)
Rinse in clean hot water.
(4)
Immerse for one hour in a solution containing five percent by weight of sodium dichromate, at 140°F to
160°F.
(5)
Rinse in clean hot water.
(6)
Rinse in hot water (160°F to 210°F) with the rinse maintained at pH 3 to 5 by the addition of flake chromic
acid or proprietary mixtures of chromic and phosphoric acid. Surfaces to be painted shall be treated with wash primer
conforming to DOD-P-15328 or MIL-C-8514.
Section II. PAINTING
3-6. APPLICATION
The first coat of paint of primer shall be applied to a dry, clean surface as soon as is practical. The coatings shall be
applied in an ambient temperature 50oF, or higher. The paint and surface shall be approximately the same temperature
except when hot spray is sued. Painting shall conform to the finish systems listed in tables 3-3 and 3-4 and shall be
applied by any method (dip, flowcoat, brush or spray) which will deposit the dry film coat-thickness specified in table 3-1.
Panels or subassemblies prepainted prior to the final assembly shall be treated and painted as specified herein. A
smooth, even surface, free from runs, sags, or other defects which might interfere with the application and adhesion of
subsequent coats, shall be applied. When applying the priming coat, sufficient time must be allowed for the paint to dry
prior to applying the finish coat. Baked finishes, except on materials that would be adversely affected by such treatment,
will be permitted if the baked finish conforms to performance requirements of the applicable paint specification.
NOTE
CARC primers and coatings cannot be applied using dip or flowcoat methods.
3-7. FILM THICKNESS
The dry film thickness of some of the more common coatings are listed in table 3-1. For other coatings, reference
individual specifications.
Change 3 3-4
