The weather resistance of Corten steel gives it special characteristics.
It can be placed outdoors without any maintenance, so architectural and artistic elements such as sculptures, wall cladding, fencing, railings, garden furniture, aesthetic and functional garden elements (lawn dividers, tree stakes, vineyard posts, planters, fountains, and more) can be left outside without any intervention. Over 2–3 years, without using an accelerator, the patina stabilises and develops its final colour. All of this without the need for painting or further maintenance.
The steel does not need surface treatment because the oxidised Corten layer forms a film that prevents water and water vapour from entering the material. This prevents further oxidation of the material, and therefore no additional protection of the steel against weather conditions is required, such as galvanising or protective coating.
In the event of mechanical damage to Corten, do not worry—over time, the patina will form again on the damaged areas.
Surface corrosion forms on the material due to weather exposure, so for indoor use the material must be oxidised using chemicals.
For outdoor use, no accelerators are required; the protective layer will form on its own sooner or later depending on the specific weather conditions at the application site. During maturation, material left to corrode naturally without chemicals may develop different shades of patina. If the desired result is an approximately uniform colour, we recommend applying an oxidation accelerator (activator).
Surface varnishing (passivation) is entirely up to the customer and the desired final finish.
We recommend it only for indoor use and after the corroded layer has matured well, as varnishing too early on an insufficiently corroded layer may cause it to peel off together with the varnish.