What are Corten Steel Sheets?

Corten steel sheet is also known as weathering steel. This is because corten sheet steel develops a beautiful dark brown colour when it is left untreated and exposed to wet and dry weather conditions. Over a period of time, it develops a layer of oxidisation, this gives it a rusty appearance whilst also providing a protective layer to prevent any further corrosion. This makes sheet corten steel a great option for outdoor spaces, creating a unique industrial style.

What Does Corten Steel look like?

When you first receive corten steel sheets from London Metal Store, they will have a smooth, silver-grey surface. At this stage, corten steel looks very similar to regular steel. Many people are surprised to find that Corten Steel starts off with a plain appearance.

Once corten steel sheets are exposed to outdoor weather conditions, they start to change. In the early weeks, the steel reacts with moisture and oxygen in the air, forming a light orange and copper coloured tones across the surface. This early stage can often appear patchy or uneven. This is part of the natural process in which the surface slowly starts to oxidise, creating areas of rust whilst other areas are still transitioning.

Over the following months, the colour deepens. The surface gradually shifts from bright orange to rich shades of brown. The texture becomes more matte and rough giving the the steel its signature aged appearance. The special part about corten steel is that each sheet weathers in its own way, resulting in a unique finish every time.

History

Corten steel was originally developed in the United States during the 1930s by U.S. Steel. It was originally designed to withstand harsh outdoor environments without the need the constraint painting or maintenance. 

Over time, architects and designers began to appreciate the material for its distinctive appearance rather than the durability. Since then, corten steel has been widely used in industrial settings and modern architecture across the world. The metal's ability to develop a natural rusted look without compromising its structure has made it a sought after choice for creating bold, weathered designs.

Today, corten sheets continue to be popular for functional and decorative purposes, especially in outdoor environments.

The Patina of Corten Steel

One of the key features of corten steel is that the rust layer does more than just create an attractive look - it actually protects the steel underneath. As corten steel is exposed to wet and dry cycles, it forms a stable layer of rust that acts as a barrier against further corrosion. This ensures that the material is durable in outdoor conditions. Unlike other metals that need to be painted or coated utilises its natural weathering process as its protection. 

The full weathering process can typically take from six months to a few years depending on climate. Humid and rainy environments tends to speed up the process whereas drier conditions can slow it down. It is important to note that corten steel will not weather properly if its kept indoors. The metal must be exposed regularly to moisture within the air otherwise the steel will struggle to develop its distinctive rusted finish.

How to speed up weathering process

Some people decide to take it upon themselves to speed up the weathering process due to the significant amount of time it can take for the steel to achieve its patina naturally. Here are some ways you can achieve this.

1. Use a Saltwater or Vinegar Solution - By spraying the steel with a mix of salt and water or white vinegar with hydrogen peroxide these acidic solutions can help trigger the oxidisation process.
2. Alternate Wet and Dry Cycles - Corten steel weathers faster when exposed to repeated moisture followed by drying. To enhance this, spray the surface with water, allow it to dry, then repeat the process.
3. Place in a humid or exposed environment - Environmental factors such as humidity, rainfall and airflow significantly impact how quickly the patina forms.

Corten Steel Sheet from London Metal Store

When shopping for the right metal supplies, you want to make sure you’re selecting options which meet your demands. Here at the London Metal Store, our customers can enjoy peace of mind that all metal products they order live up to the very highest standard for quality, accuracy and durability.

If you’re looking to buy corten sheet steel in its initial state, you’re in the right place. Take a look at our sheets of corten steel options today and find the best corten steel price. Our products can also can be tailored to a size and shape that suits you. Don’t hesitate to contact our team if you have any questions or queries. Call us on 0203 002 63 53 or drop us an email at sales@londonmetalstore.co.uk.