Painting Surface
Galvanized Steel
Galvanized steel is steel protected by a zinc coating that slows corrosion. New galvanizing may also carry oil or a passivation treatment that interferes with paint adhesion.
Galvanized steel paint compatibility
Latex, spray, epoxy, and polyurethane coatings can work on galvanized steel when the products approve zinc-coated metal. Conventional alkyd paint should not be applied directly because it can react with the zinc and peel.
| Paint | Compatibility | Preparation | Primer | Finish | Guide |
|---|---|---|---|---|---|
| Latex paint | Good with a galvanized-metal-compatible system | Remove oil, grease, passivator, white rust, and loose coating, then create the required surface profile. | Use a water-based or other zinc-compatible primer when the selected system requires it. | Choose a topcoat rated for the location and weather exposure. | — |
| Spray paint | Product-specific | Clean and prepare the galvanizing as directed without unnecessarily removing the protective zinc layer. | Use an aerosol bonding primer approved for galvanized steel unless the topcoat permits direct application. | Follow the full system's recoat and cure instructions. | — |
| Epoxy paint | Excellent in an approved protective system | Remove contamination and prepare the zinc surface to the coating specification. | Use the specified galvanized-steel-compatible epoxy or bonding primer. | Observe the system's recoat, service, and full-cure requirements. | — |
| Polyurethane paint | Good as part of an approved metal system | Clean and prepare the galvanizing to the coating manufacturer's specified standard. | Apply over the compatible primer or intermediate coat required by the system. | Choose a finish rated for the expected wear, chemicals, and weather. | — |
| Alkyd paint | Poor for direct application | Do not apply conventional alkyd paint directly to galvanized zinc. | Use only a complete manufacturer-approved barrier-primer and topcoat system. | An incompatible coating can form a soapy film and peel. | — |
Sources: Sherwin-Williams galvanized-metal peeling guidance, Sherwin-Williams surface preparation guidance, Sherwin-Williams Macropoxy EG-1 VHS, and Rust-Oleum Universal Bonding Primer.
Galvanized steel painting articles
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