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|  MILL87177A
either indicated or actual, nor does it commit the Government to accept defective
material.
4.2 Classification of inspections. The inspection requirements specified herein are
classified as follows:
a. First article inspection (4.4)
b. Quality conformance inspection (4.5).
4.3 Inspection conditions
4.3.1 Test conditions. In general, physical tests contained in this specification shall be
made under controlled atmospheric conditions having a relative humidity of 50 + 5
percent and a temperature range of from 21C to 27C (70F to 80F). Waiver of this
requirement may be permitted where proper conditioning facilities are not available for
control testing. However, for referee purposes, the specified tests shall be made upon
the compound under the specified atmospheric conditions.
4.3.2 Specimen for test
4.3.2.1 Materials. The material for the test disks and panels shall be carbon steel
conforming to composition 1020 of MILS7952.
4.3.2.2 Size of test disk and panels. Test panels for tests requiring compound coatings
shall be 2 by 4 by 1/8 inches; the dryness tests shall require disks with a diameter of
21/8 inches and a thickness of 1/16 inch.
4.3.2.3 Preparation of test panels (or disks). Panels (or disks) shall have all sharp
edges and burrs removed and shall have all holes chamfered to prevent injury in
handling. The panels (or disks) shall be surface ground and hand polish with a 240 grit
silicon carbide or aluminum oxide cloth or paper to produce a surface finish of 10 to 20
microinches (rms). Iron oxide or socalled "wet or dry" papers or cloths shall not be
used.
4.3.2.4 Cleaning test panels (or disks). The utensils and cloths used in the cleaning of
test panels (or disks) shall be clean and free of contamination. Solvents shall be fresh
and renewed frequently. In all stages of treatment the handling of panels (or disks) with
the bare hands shall be avoided. The panels (or disks) shall not be permitted to contact
contaminated surfaces during the cleaning procedure and shall be handled by tongs
and hooks during and after dipping. After polishing, they shall be cleaned with a
surgical gauze swab, in a beaker of hot mineral spirits conforming to type I of
TTT291. Cleaning and scrubbing shall be followed by dipping in (1) a second
container of hot mineral spirits, (2) boiling 95 percent methanol, and (3) boiling absolute
methanol. The panels (or disks) shall be allowed to dry and shall then be stored in a
desiccator until ready for use. If storage of more than 24 hours occurs, the surface
preparation shall be repeated starting with the hand polishing.
4.3.2.5 Coating of the test panels (or disks). Application of the compound to the test
panels (or disks) shall be carried out under the atmospheric conditions of 4.3.1. The
panels (or disks) shall be held at an angle of 30 degrees from the horizontal. A coating
of the compound shall be sprayed on the panels (or disks) from a pressurized container
or a container conforming to MILS22805 held 12 inches away. After ten minutes, a
second coating shall be sprayed on. The combined thickness of the two coats after
drying shall be 1.2 to 1.5 mils. After application they shall be conditioned for 24 hours
6
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