What is the primary purpose of using zinc-chromate or wash primers?

The primary purpose of using zinc-chromate or wash primers is to inhibit corrosion. These primers contain zinc chromate, which provides a protective barrier that adheres well to metal surfaces and prevents moisture and oxygen from reaching the underlying metal. This is crucial in aviation and other industries where metal components are exposed to potentially corrosive environments.

Zinc-chromate primers create a chemical bond with the metal and provide cathodic protection, which helps to prevent rust and corrosion over time. This protective quality is essential to maintaining the structural integrity and longevity of aircraft components.

While enhancing color vibrancy, serving as a finishing coat, and improving drying time are aspects of paint and coating processes, they are secondary to the primary function of corrosion inhibition provided by these primers.