The primer covered by this specification is intended primarily for use as a corrosion inhibiting primer on aluminum aircraft or airborne equipment metal surfaces either alone or top coated with lacquer or enamel. It should be applied to a dry film thickness between 0.3 - 0.4 mil. For non-aircraft or airborne equipment and on iron or steel surfaces it should be applied to 0.6 - 0.8 mil dry film. The primer is satisfactory for application over a wide range of temperature and humidity conditions, this property being controlled by the strict compositional requirements. This primer is intended for spray application over surface-treated metal or pretreatment coating. If used for dip or flow-coat application, the suitability should be determined by the user. Suggested tests are as follows: