2-15. PRIMER COATING (TT-P-636)
Characteristics. Primer coating TT-P-636 is a red or brown iron oxide, alkyd-resin base primer that thas good
adhesion, durability and flexibility, and covers in one coat. It has good resistance to weathering, although its intended use
is as an undercoat.
This primer must NOT be used on the inside of drinking water tanks or on
As a priming coat on synthetics, wood, bare or phosphate-treated ferrous metal parts (of motor vehicles,
guns, gun mounts, tanks, and metal shipping containers), and other Ordnance materiel.
As a sealing undercoat on the wooden parts of motor vehicles.
This primer should not be used on steel vehicles, vessels, or structures that are
exposed to acid fumes.
Brushing. Apply as issued or by thinning with not more than five percent by volume of thinner. Apply one
coat of primer for a two-coat finish and two coats for a three-coat finish.
Spraying. For spraying, thin with 15 percent by volume of mineral spirits paint thinner, TT-T-291, or
synthetic enamel thinner, TT-T-306.
Before touching, air-dry for 20 minutes to two hours.
For thorough drying, air-dry for 18 hours or bake for 45 minutes at 250°F (121.11°C).
Recoating is permissible after air-drying for 10 hours.
Thinner. Thin primer as required with mineral spirits paint thinner, TT-T-291, or gum spirits turpentine, TT-T-801.
Olive-drab, rust-inhibiting enamel, TT-E-485, may be used in lieu of enamel TT-P-636.