(f)
Decant into another container without transferring undissolved cal-cium sulfate.
(2)Conversion Coating Application
CAUTION: THE FOLLOWING PROCEDURE IS NOT APPLICABLE TO ADHESIVE BONDED PARTS
OR ASSEMBLIES OR AREAS WHERE THE BRUSH-ON SOLUTION MIGHT BECOME
LODGED OR ON LOCAL AREAS BARED SPECIFICALLY FOR GROUNDING OR ELEC-TRICAL BONDING PURPOSES.
(a)
Wipe treatment area with dry clean cheesecloth to remove loose pati-cles and residue.
(b)
Wipe with cheesecloth dampened (not saturated) with solvent, series
88 (Ref. SOPM 20-30-88). Repeat using clean cheesecloth until no
visible residue transfers to the cheesecloth.
(c)
Allow to dry for a minimum of 15 minutes. Refer to para.2.C.(2)(c)
for water break test to determine cleanliness.
(d)
Mask off dissimilar metal inserts, except chromium, nickel, corro-sion resistant steel, or titanium.
CAUTION: SEVERE RUBBING OF WET SURFACE CAN CAUSE COATING DAMAGE.
(e)
Apply solution by swabbing with brush, swab, swatches, cellulose
sponge or white blotting paper. Maintain a continuous wet film until
metal surface becomes dull golden to dark brown in color.
(f)
Rinse with clean cold water.
Volume 1
20-50-00
Page 6
OCT 01/01
CORROSION PREVENTION MANUAL
GENERAL INFORMATION STANDARD TREATMENT METHODS
CAUTION: DO NOT DIRECT HIGH PRESSURE AIR TO SURFACE WHILE DRYING AS COAT-ING IS STILL SOFT.
(g)
Allow to dry at ambient temperature. Force air dry if possible.
(h)
Apply original finish.
(i)
Remove masking and protective covering.
4. Surface Treatment for Carbon Steels
A. General. Bare surfaces of carbon (alloy) steels are highly reactive when
exposed to the environment. Carbon steel is either cadmium or cadmiumtita-nium plated after machining and heat treatment. Steel parts absorb hydrogen
during processing operations and in service when hydrogen may be produced
and diffused into the metal. Hydrogen absorption, can cause crack initiation
and propagation and result in delayed brittle fracture when the part is
under sustained tensile strength. The susceptibility of steel parts to
hydrogen embrittlement increases as hardness and strength increases.
B. Surface Treatment. Steel parts heat-treated to 180 ksi and below are not
considered susceptible to hydrogen embrittlement while steel parts heat-
treated to 220 ksi and above are highly susceptible to hydrogen embrittle-ment and must be plated by Low embrittlement processes. In order to preclude
the use of conventional plating process, reworked surfaces of all carbon
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