Commercial Painting Problems & Solutions: Paint Peeling From Metal SurfacesPenncoat Inc
Metal Doors, Garages, and Other Metal Substrates Can be Susceptible To Coating Failure If not Prepped and Planned Properly
Paint peels all the time. It’s inevitable. However, that inevitability may occur over the span of years, or decades. And decades is the preferred duration. But to achieve decades, you’ll need to provide the appropriate prep work, to ensure that the coating has the greatest chance to adhere to the substrate.
But each substrate varies with what it requires, and those requirements are often temperamental when dealing with metal. The more porous the surface, the easier time a coating has to adhere. And steel and metal don’t have very porous surfaces, so it’s important to follow strict guidelines to ensure that the coating can last.
- Remove and Existing Rust or Failed Coating – Just as any situation, you’ll need to make the effort to remove the existing rust and peeling paint. Rust can be removed fairly easily with a wire brush and scraper. But if you have a lot of areas, then you might want to consider an abrasive blaster. The abrasive blaster will remove the rust, leaving you with a clean surface to apply the paint. Or, if you have a lot of failed paint, then you can use the same tools: a wire brush, or an abrasive blaster. This will remove the paint flakes and the rust. But, be forewarned, the water will cause the steel to flash-rust. Flash rusting typically occurs within a few hours of removing the paint. But there are products you can try to prevent it. But they work with mixed results.
- Rust-Inhibitive Primer – After removing the loose paint and rust, you’ll want to apply (2) coats of a rust inhibitive primer. The rust-inhibitive primer penetrates into the steel, which prevents moisture and water-based coatings to access the corroded areas. POR15 is a rust inhibitive primer we frequently use. It has a low viscosity, which allows it to cross-link into the substrate, and to create an impervious bond that water cannot bleed through.
- DTM – DTM’s (Direct To Metal) paints are specifically designed to handle the typical conditions that steel is subjected to. Many of them are made from latex, giving it a flexible property so that it can bend and flex under the changing climate. This helps the top coat last longer, without forcing it to break under the stress of expansion and contraction.
But if steel isn’t outdoors, then you could consider an alkyd enamel. That will provide you with excellent self-leveling properties, while also granting the strong, hard surface that a person would prefer from a coating. So, your conditions and environment will dictate what type of top you’ll want to use.
But regardless of the area, you’ll need to use the same amount of prep, to ensure that your coating will last decades, instead of weeks, or even days.