Epoxiprimer

Epoxiprimer, or epoxy primer, is a protective coating applied as the first coat to metal surfaces. It uses an epoxy resin binder cured with a hardener in a two‑component system, forming a durable film with strong adhesion and resistance to chemicals. Many formulations incorporate corrosion-inhibiting pigments, such as zinc compounds, to provide barrier protection or sacrificial protection in galvanic systems.

Epoxiprimers are widely used on structural steel, pipelines, ships, bridges, and industrial equipment, and can be applied to aluminum and galvanized substrates with proper surface preparation. They offer excellent adhesion, abrasion resistance, and low permeability, helping to extend the life of topcoat systems. Some variants are designed as zinc‑rich primers for enhanced sacrificial protection, while others focus on barrier performance without galvanic action.

Two main variants exist: solvent‑based epoxiprimers and water‑based (low‑VOC) systems. They require compatible topcoats and careful surface preparation. Limitations include sensitivity to moisture during cure, the need for correct mixing and pot life management, and restricted recoat windows if the timing is not followed. They can have longer cure times at lower temperatures and may require specific surface cleanliness standards prior to application.

Application and preparation guidelines emphasize a clean, dry surface, typically achieved by blast cleaning or equivalent methods, followed by proper drying. Film thickness is controlled according to the system, and curing conditions influence film properties and recoatability. Safety considerations include handling with appropriate ventilation and PPE due to solvents and curing agents. Storage should protect against freezing and maintain container integrity to preserve shelf life.