grain storage facilities

Which aggressiveness category of environment according to ISO 12944 is typically assigned to the external surface of metal grain silos situated outdoors in rural areas, and why is this important when selecting a paint?

Primarily C3 "Moderate" or C4 "High", depending on the region. High humidity, temperature fluctuations, exposure to agricultural chemicals increase the corrosion effect.

For the finish coating of grain storage, two‑component polyurethane enamels are most commonly used rather than epoxy ones. Why is polyurethane preferred over epoxy for exterior applications, given that both materials are durable and chemically resistant?

Polyurethane enamels exhibit high resistance to ultraviolet radiation (not prone to fading and bleaching), unlike epoxy materials.

What should be considered when selecting a coating system for grain silage?

The walls of the silo are subjected to vibrations, pressure from the stored material, and temperature fluctuations. Consequently, the coating must exhibit high elasticity and flexibility, preventing damage and crack formation. Excessive coating thickness can adversely affect the coating’s durability.