Aluminum does not rust, but it does corrode. Rust causes metal to change in color and consistency, making it easy to spot. However, aluminum corrosion is often more subtle. Learn more about the different forms of corrosion aluminum is susceptible to and its corrosion resistant properties.
Can Aluminum Rust? No.
First off, it’s important to understand that aluminum is a highly reactive metal, especially in its pure form. Technically, pure aluminum would dissolve when exposed to water. However, the metal’s reactivity comes in handy in protecting itself from the elements. When exposed to oxygen in the air, water or soil, aluminum reacts to form a thin coating of aluminum oxide that chemically bonds to its surface.
Aluminum oxide hardens onto the metal as a greyish-white powdery substance, similar to how rust develops on metals like steel. The difference, however, is that while rust flakes away, exposing more raw metal to corrosive elements, aluminum oxide seals aluminum’s surface preventing anything else from reacting with it.
Does Aluminum Corrode? Yes.
Although aluminum has an edge on many other metals, it’s not immune to corrosion. While the protective aluminum oxide layer is very resistant and can renew itself after sustaining damage, certain factors may cause it to become unstable.
The most common type of aluminum corrosion is galvanic corrosion, which occurs when aluminum comes in contact with other metals. Galvanization occurs when two different types of metals are positioned in a way that forms an electrical circuit. While one metal is strengthened, the other is weakened. Because aluminum is such a reactive metal, it typically ends up becoming the weakened metal.
Extreme pH levels may also cause aluminum corrosion, as they have been known to break down the protective coating faster than it can repair itself. Typically, aluminum falls well in a pH between 4.5 and 8.5, potentially causing an issue in climates with clay soil.
Learn More About Protecting Your Metal from Rust and Corrosion
Get Your Aluminum From Tampa Steel & Supply
While aluminum is a strong and durable metal that is great for all kinds of building and construction projects, you can give it a little extra corrosion-fighting power with the right protection. At Tampa Steel & Supply, we not only provide quality aluminum, but the products you need to protect it, too! View our selection of paints and primers, or give us a call at (813) 241-2801 to learn more about keeping your aluminum shiny and smooth.