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A sample of the sheets shall withstand a cyclic corrosion test for a
minimum of 2014 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 [8][10], [few
blisters][no blistering], as determined by ASTM D 714; no rusting, as
determined by ASTM D 610; and a rating of [6][7], less than [1.5 mm (1/16
inch)][3 mm (1/8 inch)] creepage from scribe as determined by ASTM D 1654.
2.2.1.2
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
fracturing to the naked eye.
2.2.1.3
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 gloss finish is not required by paragraph
"Specular Gloss".
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Coating sample shall withstand weathering test of 5000 hours , in
accordance with ASTM D 4587 and ASTM G 154, Type D, without cracking,
peeling, blistering, loss of adhesion of the protective coating, or
corrosion of the base metal. Protective coating with an adhesion rating of
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.]
2.2.1.4
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.
2.2.1.5
Impact Resistance
Factory-painted sheet shall withstand direct and reverse impact in
accordance with ASTM D 2794 13 mm (0.50 inch) diameter hemispherical head
indenter, equal to 1.5 times the metal thickness in mils, expressed in
inch-pounds, with no cracking.
2.2.1.6
Abrasion Resistance Test
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NOTE: The 70 percent polyvinylidene fluoride (PVDF2)
finish has a minimum abrasion resistance of about 65
liters per 0.025 mm (65 liters/mil) of coating
thickness. A 0.030 mm (1.2 mil) PVDF2 coating will
resist 80 liters of sand and a 0.035 mm (1.4 mil)
PVDF2 coating will resist approximately 100 liters
SECTION 07412
Page 18
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