Does Copper Rust?

Does Copper Rust?

Whether you’re an architect, builder, or contractor, you’ve likely looked into architectural copper for your next project. It’s a great material that offers a tremendous wealth of benefits, but there’s one outlier we find everyone asks first: “does copper rust?”. A serious concern for any diligent constructor, it’s important to know whether a core material is going to withstand the test of time, or wither away, as well as what it will look like in a few years time. 

First, What Exactly Is Rust?

Before we can even answer the question of whether or not architectural copper rusts, it’s important to first understand what rust is. Rusting is what occurs when iron or other metal alloys are exposed to oxygen, whether it be from air or by exposure to water. Rust produces an unsightly yellow, red, or brown when iron oxidizes. 

With that said, not all metal oxidation creates rust, as rust is unique to iron and iron alloys only. Other metals undergo the same oxidation process, but it leads to corrosion, rather than rust. Thus, copper does not rust!

So Then What Is Corrosion?

Rust is simply a form of corrosion that’s unique to iron and iron alloys. So then what does it look like on architectural copper? As copper oxidizes, rather than receiving the reddish brown hues, architectural copper will become a stunning blue-green color known as patina following oxidation. 

What Can Accelerate Copper Corrosion?

Copper and copper alloys will naturally corrode over time when exposed to the atmosphere, however some key elements that may accelerate copper corrosion include:

  • Heat
  • Seawater & Rain
  • Acidic Compounds

Copper will first tarnish into a darker color before settling on the patina color. 

Is Corrosion Bad For Architectural Copper?

Whereas rust will significantly impact iron and iron alloys’ utility, copper oxidizing actually has some unique benefits. Not only does it enjoy the aesthetic benefits of the patina, but oxidized copper will actually protect it from further exposure to oxygen, stopping corrosion from occurring further. 

Interested in learning more about architectural copper for your next project? No worries! Contact Wieland-Wrisco today to discover how we can assist in supplying your next project.