Tests have been conducted on three types of decals: water, solvent, and cement applied with and without topcoats of clear lacquer and clear varnish. Four test procedures have been used for estimating the durability of the three types of decals, namely: 1) hydrocarbon solvent immersion;2) humidity-cold cycle;3) accelerated light and water;and 4) outdoor exposure.nTests indicate durability of the decals in the following order: best, 1) cement applied;next 2) solvent applied;least, 3) water applied. Topcoats increase durability of each type.nTopcoats, are not required for good grade decals for average interior use, but should be used over decals exposed to high humidity and severe outdoor exposure conditions.nA revision of Federal Specification UD-D-171, “Decals” with inclusion of MIL-D-8634A and MIL-D-8635A in one speci¬fication is recommended.
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