Corten (COR-TEN) ~ the material for trend-conscious

Cortenfactory creates durable furnishing designs for all year round use. We combine patio floor ideas with a glam living room for private / public environments. Maintenance-free steel wall & iron fences with graphic patterns that can be illuminated (metal privacy screens, modern pergola, modern room dividers). Laser cut sheet metal wall / decorative panel as partition wall or even 6ft fence. Beautiful to decorate with both indoors & outdoors as trellis panels.

Corten (COR-TEN) is an alloy steel, which means that you melt several metals together into a mass to make them better in some way. What distinguishes Corten steel from ordinary steel with rust is its content of copper, chromium, manganese and nickel. This composition makes it a relatively expensive but durable material that is maintenance free.

U.S. Steel holds the trademark under the name COR-TEN. Today, there are variants on the market that have a similar composition and properties as the COR-TEN brand. Even simpler variants of steel that do not contain copper can rust and resemble Corten in appearance. However, these are not as durable and will rust faster. It is therefore important to ensure the composition of what you buy to ensure that it really is Corten.

Nowadays, it is becoming more and more common to use this durable, maintenance-free and very beautiful material for various artistic constructions such as facades, pots and sculptures.

Durability of Corten & tips on how to speed up the rust process

The beauty of Corten (COR-TEN) is that it changes over time. This makes the material come alive. Corten, which is a weathering steel, achieves a beautiful deep reddish-brown color under the influence of weather and wind. Changing weather conditions transform its surface from ordinary steel paint to eventually achieve a thin protective reddish-brown rust layer. The oxidation process of the steel surface that starts with the help of weather and wind. This process makes the corrosion of the steel to stop over time. The rust layer that forms thus becomes protective of the Corten steel and adheres to the metal surface which prevents moisture from penetrating. The insulating patina resists corrosion, requires no painting or weather insulation. It does not compromise structural strength. A rusty surface layer is already visible after 6 months of outdoor use. In the beginning, COR-TEN takes on a light reddish-brown color. The longer the steel is exposed to the elements, the darker shade of brown is achieved. It takes about 2 years for the steel to achieve an even rusty surface if you don’t speed up the process. The fire barrel has been outside for about 4 months and the supporting wall below shows color on the Corten steel after about 3 years of outdoor use.
Halo, metal coffee table may be used as drink table or fire barrel. It is a beautiful modern pool table especially as illuminated coffee table. The Cortenfactory creates unique minimalist lighting & furnishings for private & public environments. Design for garden, patio & home decor.
Image shows color of rust after 3 years outdoor usage

Expose Corten to moisture. Oxidation occurs faster in the presence of moisture. Spray water on the Corten surface with a flower sprayer to increase the humidity around it. You can also place Corten in a moist environment, for example near a water source or in a greenhouse. Preferably with good ventilation.

To enhance the rusting effect on steel, saltwater or a mixture of vinegar and water may be applied. To create a uniform and subdued rust color, saltwater can be used, with a suggested ratio of 1 part salt to 4 parts water. Meanwhile, a mixture of vinegar and water produces varied and lively colors, including orange, brown, blue and green. A commonly suggested proportion is 50/50 vinegar and water, which induces rust formation without excessively damaging the steel. Experimentation with different parts of salt and vinegar concentrations is advised to achieve the desired result. Finally, even applying a low concentration of hydrogen peroxide (3%) results in a reddish-brown color to your Corten. Corten steel rust formation takes time, and exposure to these mixtures accelerates the process but may still take up to a week. Before treating the entire surface, experimentation and testing on small areas of the steel is recommended, followed by rinsing the surface thoroughly.
Påskynda rostprocessen

There are also a number of commercial rust accelerators that can speed up the oxidation process of Corten. These products usually contain chemicals that promote rust formation. Follow the manufacturer’s instructions when using such accelerators, as they may vary depending on the specific product.

We have used Rost Patina on the grate placed in the fire bowl. 

Example of appearance after using rust patina

If you want to reduce the rust process there are also sealers for that.

Tips for using Corten for outdoor use

Corten is a maintenance-free and durable material. Our planters consist of 3 to 5 mm thick steel to last long term. If you want the product to withstand the outdoor environment for at least 40 years, you should use 4 mm thick steel or more.

To increase the life of the steel, one should avoid water constantly resting against the Corten steel. That since this means that the rust process continues with undiminished strength. If you buy a Corten planter that you intend to use for many years, it is wise to use an inner pot, bubble wrap or insulation. That way you create a distance between steel and soil.

Our square and rectangular planters have a decorative frame to hide any insulation in a nice way.

Keep in mind that the steel rusts off somewhat in the first two years. If you worry about rust stains, you should consider where to place the steel to avoid unwanted discoloration. Feel free to place Corten steel on a stone slab, some of our pot trays or the like.

Square Trendsetter Corten steel planter. Unique plant pots of high quality with optional self-watering. Modern planter with drain in rusty Corten or as black lacquered rectangular indoor planters.
Glow, a modern bird bath in Corten for several uses. The bowl is also suitable as a plant bowl, outdoor fire place, or water lily bath.

You avoid rust stains from, for example, a birdbath by brushing on a plant-based candle wax from soy, coconut or rapeseed. It protects well and is harmless to the birds. Melt the wax over low heat and brush on a thin, even layer over your rust.

Tips when using Corten indoors

Corten steel is excellent to use indoors and offers a warm and exclusive tone in the home. Corten welds can let moisture through if you add to too much moisture. There are simple tricks to avoid any rust stains. A simple trick for the pots is to use an inner pot in plastic and a plastic saucer to catch any excess water.

If you are worry about rust stains, you should place the steel on, for example, glass, tiles or the like, which is easy to clean if discoloration should occur. Another alternative is to spray matt clear lacquer on the rusty Corten to avoid rust stains. You can also create a small distance between the bottom of, for example, a pot, by putting them on few crowns to get air flow circulation.

Saucer and upper frame
Spray lacquer

Removal of rust stains from Corten (COR-TEN)

There are a number of tricks to remove rust from various surfaces. If you get rust stains on glass, you can remove it with the help of regular toothpaste and a dish sponge. Trim with rotating motions until all rust has dissolved and then rinse off.

Baking soda is also effective in removing rust. If you have a stone surface, you can sprinkle on baking soda, pour on a little water and leave to dissolve the rust. To clean wood, you can use oxalic acid to remove rust.

If you have really dark spots of rust on glass or stone, you can sprinkle oxalic acid, pour on some water and let it soak for up to 2 days before rinsing off.

Tips for lighting Corten

Art Cube made of Corten. Rust sculpture
Tulip round, statue, monument, garden lighting, garden design. Cortenfactory creates durable furnishing designs for all year round use. We combine patio floor ideas with a glam living room for private / public environments. Laser-cut Cor-ten steel metal design for interior & exterior use. Modern garden statues with decor lighting & architectural metals for unique homes.

Corten steel is incredibly beautiful to illuminate. It creates an artistic shimmer and gives life to your home even in winter.

Color temperature (Kelvin)

When you are looking for LED lighting products for homes and homes, people often talk about color temperatures between 2700K and 3000K. Although both are often considered “warm white”, there is a noticeable difference between the two options.

2700K provides a very nice and warm atmosphere. It is an excellent choice for living rooms and bedrooms where you want to promote relaxation. 3000K instead gives a more pure neutral white color compared to 2700K which in some cases can be perceived as yellow. 3000K is often used in kitchens, laundry, bathrooms and home offices. That where visual tasks are more common and warmth and relaxation are not the primary goal.

In the picture below with the statue Tulip we have used 3000K. As the Corten itself has a brown tone, color recycling in the warmer direction. Therefore, 3000K is often preferable to 2700 K.

Strength when illuminating Corten steel

Another issue to consider when it comes to lighting is what strength you want on the light. Via the traditional light bulbs this was stated in Watt. Nowadays, people instead talk about the lumen in relation to LED lighting. If you want to illuminate outdoors at night when it is naturally completely dark, great contrasts are created with spot lighting. Then a rule of thumb is not to use too high a level on the lumen. That since it creates too great contrasts. The led strips we offer therefore have 460 lumens (5 watts).

IP classification

Another point to consider is IP classification. This scale indicates how well the lighting equipment is protected from water, dust, intrusive objects and touch. A rating of IP 44, for example, is not waterproof but prevents water from reaching electrical parts. In order for a product to be considered completely waterproof and withstand prolonged immersion in water, it must have an IP rating of 68.


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