|For more examples.
Metal is a very organic element, add to this an element of decay holding both a history and a future.
The idea that the metal has been rusting over time, in the weather almost gives it a life of it's own.
There is a sense of history attached to the metal for example a soldier returns home from WWII and builds a shed from corrugated iron and over the years of weathering the metals rusts but inside the shed the observers the goings on, protecting valuable objects and over seeing the procession of people passing through until one day the sheds life comes to an end. The metal is salvaged and given new life as a sculpture and so the cycle continues.