VARNISHES

TM 43-0139 2-35. VARNISHES a. General. Varnishes are nonpigmented liquids that, when applied as a thin film, dry on exposure to the air and provide a protective coating. Most varnishes are clear or translucent, but certain asphaltic base materials, which are used for protection against moisture or acids and for technical purposes such as electrical insulation, are called varnishes although they are black due to the use of dyes. b. Varnishing, Moisture and Fungus Resistant (MIL-V-173). WARNING This varnish contains a fungicidal ingredient that is harmful if ingested. Observe the manufacturer's precautions in its handling. (1) Characteristics. This is a transparent, phenolic-resin base varnish. The presence of this varnish can be determined by inspection under a "black light", which activates a fluorescent dye. The dye can be added for this purpose prior to the application of the varnish. This varnish has a high dielectric strength. (2) Use. It is used as a surface or finish coat on electrical equipment and components such as coils, circuit wiring, and the chassis of radar and radio assemblies as protection against moisture and fungi. (3) Application. Apply by brush as issued, or after thinning with not more than five percent by volume of thinner. For spraying, apply after thinning with not more than 15 percent by volume of thinner. Dipping consistency depends on the type, shape, and construction of components and assemblies. The degree of thinning required is determined by trial. Use the manufacturer's recommended thinner. c. Varnish, Spar, Water-Resisting (TT-V-121). (1) Characteristics. This is a durable, waterproof varnish with satisfactory weathering qualities. It is composed of high-grade resins and polymerizing drying oils. (2) Use. Use as issued on exterior surfaces where durability is important and a high gloss is not required. It can also be used as a vehicle for exterior enamels where high resistance to the elements is required. 2-18