Specification for Painting Process and Coating Film of African Rural Lighting ready board

Facing the high temperature, high humidity, and sandstorm invasion in rural Africa, some coastal areas suffer from salt spray erosion. The carbon steel shell of the lighting Ready Board Box is painted with a double-layer coating system of epoxy primer and polyurethane topcoat. The dry film thickness of the primer shall not be less than 40 microns, the dry film thickness of the topcoat shall not be less than 40 microns, and the overall total paint film thickness shall be ≥ 80 microns; The standard configuration is 1 coat of primer and 1 coat of topcoat. If the project is close to the coast and the corrosion conditions are severe, an epoxy cloud iron intermediate paint can be added to enhance the shielding and anti-corrosion capabilities.

Before painting, the shell must undergo oil removal, rust removal, and phosphating pretreatment to ensure coating adhesion. Epoxy primer plays a role in substrate rust prevention, sealing and isolation, and prevents water vapor penetration; Outdoor polyurethane topcoat resists UV exposure, wind and sand wear, and delays fading and powdering. Weld seams, corners, and openings are areas of weak corrosion resistance, and should be thickened during spraying. The minimum thickness of the local paint film should not be less than 30 microns to avoid exposure and rusting caused by transportation bumps.

The coating acceptance is based on the GB/T9286 grid test, and the adhesion force reaches level 1 or above; Neutral salt spray test for no less than 500 hours without red rust or bubbles. The minimum total film thickness that can be implemented on the inner wall of the box is ≥ 60 microns, meeting the basic protection requirements. The entire process balances cost and durability, and is suitable for long-term outdoor installation and limited operation and maintenance conditions in rural Africa, effectively extending the outdoor service life of ready boards.