Designed for longevity in harsh environments, the rustproof iron custom door combines advanced materials and coatings to resist corrosion. The base material is typically hot-dip galvanized steel (zinc coating ≥85μm), forming a sacrificial barrier against rust, followed by a zinc phosphate conversion coating to enhance adhesion. The finish system may include epoxy primers, glass flake mid-coats, and polyurethane topcoats, achieving 1500+ hours of salt spray resistance (ASTM B117). Stainless steel fasteners and seals prevent galvanic corrosion, while design features like sloped tops, drainage holes, and sealed joints minimize water accumulation. Customization includes color, texture, and decorative elements, with options for marine-grade coatings or duplex systems (galvanization plus powder coating) for extreme conditions. These doors are ideal for coastal homes, industrial zones, or high-humidity regions, offering maintenance-free durability.