right angles.
2.4.3.5
Impact
ASTM D 2794, no loss of adhesion after direct and reverse impact equal to
1.5 times metal thickness in mils, expressed in inch-pounds.
**************************************************************************
NOTE: Use 1500 hours for kynar on galvanized steel.
Use 2000 hours for kynar on aluminum.
**************************************************************************
2.4.3.6
Humidity Resistance
ASTM D 2247, [1000] [______] hours, no signs of blistering, cracking,
creepage or corrosion on score panel.
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NOTE: MIL-HDBK-1028/1, "Aircraft Maintenance
Facilities," Section 2, paragraph entitled "Surface
Treatment," requires this for roof surfaces so
located that glare may be an operational hazard.
Manufacturers producing prefinished sheets meeting
this requirement as a standard item are limited, and
the sheets are available only in certain colors.
The fade and chalk requirements will not apply with
this low gloss. Delete them from "Factory Color
Finish."
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2.4.3.7
Specular Gloss
**************************************************************************
NOTE: Few manufacturers regularly produce
prefinished panels meeting these low gloss
requirements and such sheets are available only in
limited colors. Standard 70 percent PVF2 finish,
for example, has a medium gloss. Low gloss paint
formulations result in reduced weathering
properties. Identify individual facilities
requiring low gloss finish.
For roof of structures at airfields where glare
would be objectionable and may be an operational
hazard, the specular gloss value should be limited
to 10 or less at an angle of 85 degrees.
**************************************************************************
ASTM D 523, finished surfaces exposed to the building exterior shall have a
specular gloss of 10 measured at an angle of 85 degrees.
[2.4.3.8
Abrasion
ASTM D 968, Method A, falling sand shall not expose substrate when tested
in quantities [7.9-10.6] [13.2-15.9] gallons of sand per mil of thickness.]
2.4.3.9
Formability Test
When subjected to testing in accordance with ASTM D 522 Method B, 3 mm 1/8
SECTION 13120
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