NOTE: The results of the salt spray test will vary
depending on the thickness of the coating.
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A sample of the sheets shall withstand a cyclic corrosion test for a
minimum of 2016 hours in accordance with ASTM D 5894, including the scribe
requirement in the test. Immediately upon removal of the panel from the
test, the coating shall receive a rating of not less than 10, no
blistering, as determined by ASTM D 714; 10, no rusting, as determined by
ASTM D 610; and a rating of 6, over 2 0 to 3.0 mm 1/16 to 1/8 inch failure
at scribe, as determined by ASTM D 1654.
2.6.2
Formability Test
When subjected to testing in accordance with ASTM D 522 Method B, 3 mm 1/8
inch diameter mandrel, the coating film shall show no evidence of cracking
to the naked eye.
2.6.3
Accelerated Weathering, Chalking Resistance and Color Change
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NOTE: Low gloss finishes have relatively poor
weathering qualities. Delete the last sentence if a
low gross finish is not required by Paragraph
Specular Gloss.
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A sample of the sheets shall be tested in accordance with ASTM G 154, test
condition [UVA-340 lamp, 4h UV at 60 degrees C followed by 4h CON at 50
degrees C] [UVA-340 lamp, 8h UV at 60 degrees C followed by 4h CON at 45
degrees C] for [_____] total hours. The coating shall withstand the
weathering test without cracking, peeling, blistering, loss of adhesion of
the protective coating, or corrosion of the base metal. Protective coating
with an adhesion rating less than 4B when tested in accordance with ASTM D
3359, Test Method B, shall be considered as an area indicating loss of
adhesion. Following the accelerated weathering test, the coating shall
have a chalk rating not less than No. 8 in accordance with ASTM D 4214 test
procedures, and the color change shall not exceed 5 CIE or Hunter Lab color
difference (delta E) units in accordance with ASTM D 2244. For sheets
required to have a low gloss finish, the chalk rating shall be not less
than No. 6 and the color difference shall be not greater than 7 units.
2.6.4
Humidity Test
When subjected to a humidity cabinet test in accordance with ASTM D 2247
for 1000 hours, a scored panel shall show no signs of blistering, cracking,
creepage or corrosion.
2.6.5
Impact Resistance
Factory-painted sheet shall withstand direct and reverse impact in
accordance with ASTM D 2794 13 mm 0.500 inch diameter hemispherical head
indenter, equal to 6.7 times the metal thickness in mm, expressed in
Newton-meters, 1.5 times the metal thickness in mils, expressed in
inch-pounds, with no cracking.
2.6.6
Abrasion Resistance Test
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SECTION 07416A
Page 20
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