Corten Steel Water Feature | Urban Grow

Everything you need to know about corten steel

What is corten steel?

Corten steel is a group of steels that can be used in outdoor construction. They were designed to eliminate the need for painting and if left outside, they develop an rusted appearance within just months!

Corten steel is a type of metal with special durability properties. The term “weathering” comes from its ability to resist corrosion and tension, which means it lasts much longer than other types of common metals such as aluminum or copper for example.

The part ‘Cor’ refers to the metal’s property of corrosion resistance, whilst ‘ten’ is in reference to the metal’s strength.

How to make corten steel rust

 When you leave your corten steel out in the elements, it will naturally form a protective layer of rust.  This process can take longer or shorter depending on where you live and the weather patterns, as some areas can have long periods without any rain at all!

The process of patina formation on corten steel can take as little time or a bit more than one month, depending on the climate conditions and size panel. Ideally you want to alternate wet/dry periods so that your metal achieves an even orange color across its entire surface but if this isn't possible due weather fluctuations then don’t worry because they are only necessary for stabilizing purposes before achieving maximum maturity (patination).

Corrosion can occur naturally in the air over a prolonged period of time outdoors through weathering. Dipping or spraying salt water regularly significantly speeds up the process after just about 2 weeks.

What is corten steel made of

Corten is a unique type of steel that has some interesting properties because the metal contains elements such as copper, which influences its coloration process. Its a type of iron-carbon alloy that has been specifically designed to give it the appearance and characteristics of weathering. This makes cortens very popular in architecture because its surface develops cracks, textures over time which add beauty as well as character when seen up close or from afar! It’s a unique type of iron-based alloy that includes other materials such as carbon, silicon and manganese. The result? A rustic orange hue to the normally dark coloration found in regular steels!


Does corten steel stain paving?

The fine layer of rust on Corten can stain run-off water and while it is attractive, this could lead to quickly disfigurement for stone or concrete paving. There are ways in which you might prevent your beautiful creation from being severely damaged by discoloration though!

Water allows the discolouration of corten to run onto other surfaces. To avoid water overflowing at the joints between paving and planters, it's important to leave a five-to ten millimeter gap. This ensures that any excess water can run off with the minerals going into the gap and not run on to the surface of the paving.

Is corten steel sustainable?

Corten is a unique and sustainable choice, with no maintenance required the surface develops to an attractive rust-like appearance. Allowing steel surfaces such as these in contact With elements over time will form protective coatings that slow down future corrosion rates. The advantages of using corten steel are that it has 8 times greater corrosion resistance than common, and you don't need spray antirust paint. The only difference between the two types is in how long they will last before needing another coat--20 years for this type vs 40+ depending on what frequency spraying takes place (once every few decades). Thus, making it a naturally long lasting and sustainable product that can be used.

Can you paint corten steel?

The process of painting corten is very similar to that for painted steel. In addition, it has all the benefits associated with painting materials, plus the benefit of having its own protective coating.

Steps to paint corten steel:

  1. Ensure you are wearing a dusk mask and goggles to protect your eye. You need to use a wire brush to scrub off any rust that may be on your corten product.
  2. The surface of the material needs to be clean and dry before applying any paint. Cotton rags are perfect for this task, as they're gentle on surfaces but still effective in removing dirt from them!
  3. Apply a thin layer of primer as your first coat with an air spray if you have one, as this provides an even coat without pulling any excess material off the corten. Allow for the allocated time of your paint to dry, usually around 30mins and apply another layer of primer if needed.
  4. Apply your final coat of paint once in the same way until you have full coverage over the primer.

What is corten steel best used for? 

Corten steel is an extremely popular type of metal and due to its high level for resisting corrosion and rusting, it can be utilized in all sorts weather conditions. This therefore makes it brilliant in the garden because of its appearance and durability. Corten steel water features are one of the best materials for water displays, whilst corten steel planters and edging apply a modern contemporary appearance for a premium finish.

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