The most important thing when selecting Corten is to choose the correct grade. This is a very difficult topic to understand as there as numerous different grades alongside confusion if Corten is the same as weathering steel.Corten Steel can be cleaned off so as soon as the patina is stable, conduct a clean on all affected areas. If any runoff is unacceptable, one option to prevent it is to artificially weather the Corten before installation, although will come with additional cost and time considerations.If you do your research to make sure that the atmospheric conditions of the project area suit Corten, it will have a positive environmental impact. It will be as long lasting as any other type of building material and there is no maintenance needed.corten steel planter, many with geometric designs, which integrate naturally into the designer's architectural plans. Each tree tub is designed to allow it to be moved tree and all. The steel Tree Tubs are available in CorTen or RAL coated.