MIL-PRF-22750G
the portion of the panel which was immersed shall be almost indistinguishable with regard to
hardness, adhesion and general appearance from a panel prepared at the same time, but not
immersed and shall have no more than a 1.0 gloss unit increase over the original 60 degree gloss
value.
3.5.12 Fluid resistance. A film of the coating tested as specified in 4.7.20 shall show no blistering,
wrinkling or loss of adhesion immediately after removal. Slight initial softening is acceptable.
After a four (4) hour recovery period, the hardness of the coating shall be fully recovered.
Discoloration of the coating is acceptable and shall not be a cause for rejection.
3.5.13 Heat resistance (color change). A film of the coating shall have a color difference
Delta (Δ)E value less than or equal to 2.0 when compared to an unexposed sample of the same
batch and tested as specified in 4.7.21 using CIELAB color coordinates.
3.5.14 Solvent resistance (cure). The coating shall withstand 25 double rubs with a cotton
terrycloth rag soaked with methyl ethyl ketone (MEK) solvent, when tested as specified in 4.7.22.
Rubbing through to bare metal indicates failure of the coating due to improper cure.
3.5.15 Tape resistance. The coating shall not exhibit permanent marring caused by masking tape
applied to the coated test panels, when tested as specified in 4.7.23.
3.5.16 Corrosion resistance (type III only).
3.5.16.1 Salt spray resistance. A film of coating, tested as specified in 4.7.24.1 and examined
immediately after removal from the salt spray test, shall show no more than a trace of rusting
(ASTM D610, table I, rust grade 9) or corrosion, and no more than five scattered blisters, none
larger than one (1) mm in diameter for unscribed regions. Scribed areas shall have ratings as
specified in ASTM D1654 method A of not less than six (6) for steel or eight (8) for aluminum
panels. Upon removal of the coating, there shall be no more than a trace of rusting, pitting, or
corrosion on the panels.
3.5.16.2 Cyclic corrosion test. A film of coating, tested as specified in 4.7.24.2 and evaluated
using ASTM D1654 method A, shall have a rating of not less than seven (7). There shall be no
more than five (5) scattered blisters in the unscribed areas.
3.5.17 Super tropical bleach (STB) resistance. When tested as in 4.7.25, a film of the coating shall
show no blistering, wrinkling or film softening when examined immediately after washing with
water. Film softening shall not exceed a number 2 pencil hardness difference (see ASTM D3363)
from an unexposed film. After drying, there shall be a maximum Delta (Δ)E color change of 2.5
L*, a*, b* units when comparing a portion of the untested panel to that of the tested area. The STB
composition shall be in accordance with MIL-DTL-12468.
3.5.18 Accelerated weathering. When tested as specified in 4.7.26, the coating shall show no
cracking or loss of adhesion. The coating color difference Delta (Δ)E shall have a value of less than
9
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business