Definition - What does Epoxy Primer mean?
Epoxy primer refers to sealer that is a non-porous finish. It is primarily recommended as the first base coat over bare steel. These base coats or epoxy primers can be used over fiberglass, plastic or the black iron phosphate coating.
Epoxy primers are used for a wide variety of materials due to their strong adhesion, good mechanical ability, and durable chemical resistance in wet and high-humidity environments. The ability of an epoxy primer to resist corrosion is related to its thickness; the thicker the epoxy primer layer, the better the protection.
This primer can also be used on cracks and dents. Its bonding capacity is excellent and produces a good surface finish. Epoxy primers not only offer excellent adhesion to metals, but also serve as a proper base for extra undercoat products and top coats (paint). Epoxy primers are also commonly used to coat metal cans and containers, especially those used to contain acidic food, such as tomatoes.
Corrosionpedia explains Epoxy Primer
Epoxy primer is a sealer that produces a good surface finish on applied top coats. A two-part epoxy primer contains zinc phosphate, which acts as corrosion-inhibiting pigment. Epoxy primers can be used to waterproof materials that consequently protect the bare metal from oxidation. A dry, very clean surface is needed before applying epoxy primer. Two-part epoxy primer needs to be mixed thoroughly before applying.
Since paints in the automobile and marine industries are very important for resisting corrosion (rusting), epoxy coatings are widely used as primers to improve the adhesion of the metal surface. Epoxy primers are also used in structural steel coatings for high-build thickness with the application of only one or two coats.
A two-part epoxy primer is known as structural steel primer. It needs two components that are cured chemically through cross-linking. This two-part epoxy primer produces a film that is resistant to abrasion, chemicals and moisture. It is very suitable for use on properly prepared steel and concrete. This primer is also recommended for power plants, marine applications, water treatment plants and tank exteriors.