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| MIL-E-24763A(SH)
w/INT. AMENDMENT 1
4.6.2. Spraying properties. The enamel shall be sprayed in an "as-received" condition on a ground glass
panel (see 4.5.1.1) to a wet film thickness of 0.002 to 0.004 in (46 to 92 m). The spray gun distance shall be 6 to
12 inches for conventional spraying and 12 to 15 inches for airless. The panel shall be observed for spraying
properties in accordance with method 4331.2 of FED-STD-141 for compliance with 3.8.5.
4.6.3. Brushing Properties. The brushing properties of the enamel shall be determined in accordance with
method 4321.3 of FED-STD-141 for compliance with 3.8.6.
4.6.4. Rolling Properties. The rolling properties of the enamel shall be determined in an "as-received"
condition shall be determined in accordance with method 4335 of FED-STD-141 for compliance with 3.8.7.
4.6.5. Color Testing.
4.6.5.1. Instrumental color deviation determination. Test specimens shall be prepared in accordance with
ASTM D823 Methods C or E using a nominal 0.006-inch blade film applicator on to a clear plate glass of not less
than -inch (nominal) thickness that has been ground to a uniform finish with 1F carborundum. The color
deviation shall be determined in accordance with ASTM D2244 using an instrument having a D65 light source (10
degree observer), a 45-degree illumination angle, and a 0-degree viewing angle. The instrument shall be
demonstrated to read the color of National Institute for Science and Technology (NIST [formerly National Bureau of
Standards; SBS]) traceable standards with the color deviations allowed in 3.3. After calibration of the instrument,
measure the CIE color values of at least two FED-STD-595 color cards of the color being procured which were
received from the Government not greater than 1 year prior to the date of this use. Making not less than three
readings per card taken at one inch intervals on the long axis, one inch from the edge. Calculate E for each color
card. Determine the mean values of E and the CIE color values for the color cards. If any individual CIE color
value differs from the mean color value by more than 0.05, use a different color card and recalculate the mean
values. These mean values will be used to calculate the color difference values. Measure the CIE color values of
the test enamel using the values of three readings taken at one inch intervals on the long axis, one inch from the
edge. Calculate the mean CIE color values of the test enamel. Calculate the color difference terms. If using an
instrument that automatically calculates the color differences, enter the color card mean values as the base line for
the color difference calculations. The results of the color difference calculations shall be in accordance with the
requirements of 3.7.1 or Table VI, as applicable.
4.6.5.2. Referee color matching. If the enamel measured in accordance with 4.6.5.1 does not match the
color card when visually examined, the discrepancy shall be resolved by an independent laboratory certified to the
NIST National Volunteer Laboratory Accreditation Program for paint testing. When tested in accordance with
ASTM D823, the test enamel, prepared as in 4.6.5.1, shall visually match the FED-STD-595 color card that most
closely corresponds to the mean values calculated in 4.6.5.1.
4.6.6. Flexibility. The flexibility of the enamel shall be determined in accordance with method 6221 of
FED-STD-141. A 2-inch wide film of enamel shall be applied using a film applicator that will give a dry film
thickness (DFT) of 0.0009 to 0.0011 inch (23 to 28 m) on a smooth finished tinplate steel panel prepared in
accordance with method 2011.2 of FED-STD-141 using a mixture of 50:50 aliphatic naptha and propylene glycol
monoethyl ether. The panel shall be prepared from new, cold-rolled, rust-free, carbon steel 0.010 0.001 inch (25.4
2.5 m) thick with a Rockwell 15-T maximum hardness of 82 and finished with a surface roughness of 8 to 12
m. After application, the panel shall be air dried in a horizontal position for 24 hours at 23 1.1C (73.4 2F).
The panel shall be conditioned for hour under standard test conditions. The panel shall be bent over a -inch
(6.35 mm) mandrel. The panel shall be examined for cracks over the area of the bend in a strong light for
compliance with table IV.
4.6.7. Knife Test. The knife test shall be conducted in accordance with method 6304.2 of FED-STD-141,
using a flat portion of the panel from the flexibility test (see 4.6.6). The test results shall conform to 3.8.8.
4.6.8. Volatile organic content. The VOC in the enamel shall conform to the requirements of table III,
when determined in accordance with EPA 40 CFR CH.1, part 60, Appendix A, method 24.
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