MIL-PRF-87260B(USAF)
4.5.25.2 Test metal panels.
Test metal panels shall be pre-cleaned and photographed prior to the test initiation. The pre-
cleaning shall consist of the following steps:
a.
Degrease the plates in a trichloroethane vapor pit.
b. Soak the plates in MIL-PRF-87937 Type I alkaline detergent (10:1 solution) for 15-20
minutes until water "breaks-free."
c. Wash (deoxidize) in alcoholic/phosphoric deoxidizer for 2 minutes at room
temperature per ASTM F1110.
d.
Wash in running tap water.
e.
Rinse with distilled water.
f.
Force dry with air or nitrogen.
4.5.25.3 Test exposure.
The test exposure shall be accomplished with the plates initially dry. The cells shall be exposed
in the vertical position to allow for the drainage of condensing water. The cells may be held
together with nylon string or rubber bands to maintain constant contact between metal and
foam. The current flow measurements should be made while the specimens are at equilibrium
in the humidity cabinet. This requires that the bonding wires be run external to the cabinet for
hook-up to the electrometer.
4.5.25.4 Test intervals.
At seven intervals the plates shall be inspected and photographed for any adhesion, corrosion,
erosion, pitting, and discoloration or staining. The following procedure shall be used to evaluate
the plates:
a. The surfaces of the plates that were in contact with the foam material shall be
inspected for discoloration, deposits, and pitting. If any of these conditions exist, the surface of
the plates shall be washed in precipitation naphtha. Deposits determined as urethane materials
or elements of the baffle material, which can be removed by this process, shall be construed as
adhesion.
b. If any other marks remain on the surface of the plates after being washed in
precipitation naphtha, the surface shall be lightly polished with a nonabrasive cloth buff. Any
pits or eroded marks remaining after this process shall be construed as corrosion. Discoloration
or staining (marks that do not physically affect the surface of the plates and that easily wash or
buff off) shall not be considered detrimental.
4.5.25.5 Qualification report.
All test results and photographs shall be included in the qualification report. In addition, the test
specimens shall be forwarded to the qualifying activity for review and inspection.
4.5.26 Marker legibility test.
A marker legibility test shall be conducted to identify a suitable marker that can be used for
individual foam kit component identification before installation into the aircraft fuel system. The
marker shall be fuel compatible and shall be of a legible color (either white or black) with
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