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|  MIL-C-21067C (MI)
the tared container, covered and weighed. After removing the cover, the container
shall be placed in an oven at 100 1.1C until the sample reaches constant weight.
The covered container with the sample shall be cooled in a desiccator before weighing.
The test shall be run in duplicate (see 3.3.2).
4.6.2.2 Calculation. The percentage of total solids (see 3.3.2) shall be
calculated as follows:
weight of residue
Total solids, percent
=
X 100
weight of sample
4.6.3 Tensile strength and ultimate elongation.
4.6.3.1 Specimen preparation. Specimens shall be prepared by casting or
applying multiple coats of the material approximately 3 inches wide by 8 inches long
on silicone treated paper or other suitable release material. Film shall be allowed to
dry at 27 + 5C for 24 + 0.25 hours, then stripped from the backing and placed in a
circulating air oven at 70 + 1.1C for 24 + 0.25 hours. The final thickness of the strips
shall be 0.020 to 0.035 inch thick. After removing the strips from the oven, condition
the specimens at least 16 hours at 27 + 5C before testing (see 3.3.3).
4.6.3.2 Testing. Tensile strength and ultimate elongation of the strips shall be
determined using methods 4111 and 4121 of FED-STD-601 and die III specimens (see
3.3.3).
4.6.4 Adhesion.
4.6.4.1 Specimen preparation. The adhesion specimens shall be prepared as
follows: Clean the surfaces of nine steel panels, 3 by 6 by 0.16 inches either by
grinding, wire brushing or sandblasting and then with solvent. Cut nine strips of cotton
canvas, 2 by 6 inches. Apply two brush coats of the material over the steel panels
(primed as necessary) and 5 to 6 inches of the canvas strips. Allow each coat to air dry
0.50 hour. Apply a third coat of the material to the steel and to the canvas and roll the
two surfaces together while wet to insure good contact between the canvas and the
coating applied on the panel. After drying for one hour, apply two additional coats
over the assembly allowing 0.50 hour drying between coats. Allow all assembled
specimens to air cure at 27 + 5C for 96 + 0.50 hours before further treatment.
6
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