Structural steel Spiral Planter
The structural steel we use (type code: S235JRG2) is a very durable material, which is widely used in the industry as it represents excellent value.
We ship the structural steel Spiral Planter in its natural silver colour, and the rust layer develops in time (see rust process).
Unlike the corten steel model, the structural steel Spiral Planter does not develop a barrier layer which protects the material from corrosion. Nevertheless, structural steel has a long lifespan. Under extreme conditions (e.g. contact with salt water), structural steel will rust about 1mm every 10 years.
After the rust layer has been formed, the material does not need to be treated further.
Structural steel is 100% recyclable. Scrap metal collection points gladly accept the material and often pay for it.
- 4Rust process:
There are two ways to create the rust layer:
1. Use a rust accelerator (recommended)
You may be able to find specialised fast rusting solutions in specialised shops. However we have seen very good results using a diluted salt solution (mixture of 50 Salt to one liter water). After assembling the Spiral Planter without soil, then cleaning the oil layer with washing up liquid and water, spray this salt solution onto the Spiral Planter daily. The rust layer should form after 7-10 days*. The Spiral Planter can be filled with soil and sowed after the completion of the treatment.
2. Without using a rust accelerator
In the second method time and natural weathering cause the rusting process. The individual parts of the Spiral Planter are cleaned with washing up liquid and water to remove the oily top layer, then assembled, and filled with soil and planted. Without further treatment, the rust layer will form within 8-12 months* through the weather-related changes in humidity.
*= The duration, colour and speed of the rusting process will depend on the weather conditions and the location of the Spiral Planter.