Galvanized steel is steel that has been coated in a thin layer of zinc oxide through hot-dip galvanization. This protective coating prevents the steel from rusting for many years. However, over time, the coating can start to break down, allowing rust to form. For many applications, rusting of galvanized steel can be problematic and steps need to be taken to prevent it. There are several effective methods for protecting galvanized steel from rusting and extending its lifespan.
One of the simplest ways to prevent galvanized steel plate from rusting is to regularly clean it to remove any built-up dirt or debris. Dirt, grime, and organic matter hold moisture on the surface of the steel and speed up the rusting process. With outdoor structures like handrails, fences, or outdoor lighting, periodic washing and wiping down of the galvanized steel components will remove surface contaminants and prevent premature rusting. For a deeper clean, scrubbing the steel with a wire brush or scrub pad followed by rinsing with a hose works well.
Another strategy for protecting galvanized steel from rusting is to apply a protective coating, such as paint, wax, or oil. These coatings add a protective barrier between the steel and moisture and oxygen, which are required for rust formation. Common coatings for galvanized steel include:
• Paint - Applying 2-3 coats of rust-preventative paint specifically designed for galvanized steel or metal surfaces provides long-lasting protection from rust. Popular options include enamel, epoxy, and alkyd paint.
• Wax - A coat of car wax, paraffin wax, or beeswax protects galvanized steel and is easy to reapply. However, wax will need to be reapplied every few months for ongoing protection.
• Oil - Light machine oil, linseed oil, or tung oil create a protective coating on galvanized steel. Like wax, oil will need to be reapplied periodically to maintain protection from rust.
• Lacquer - For temporary rust prevention, a few coats of lacquer can protect galvanized steel for 6-12 months. Clear lacquer maintains the metallic gray appearance, while tinted lacquer adds a colored tint. Lacquer will need to be reapplied yearly for the best protection.
In indoor, dry environments, a single application of a protective coating may be sufficient to prevent rust for many years. In outdoor or high-moisture environments, annual re-application or touch-ups may be required to prevent rust over the long run.