sparx uses corten steel or stainless steel for its outdoor fireplaces. Both materials are incredibly strong and durable but quite different in appearance.
Corten steel
Corten steel is a metal alloy and its brown rusty colour gives the steel a very striking look. Corten steel consists of iron combined with copper, phosphor, silicone, nickel and chrome. Its strength can be compared to that of other alloyed steel types such as stainless steel. The rust-coloured and very dense oxide outer layer protects the underlying material against oxygen, resulting in a much slower oxidation process. Due to this oxide layer there is no need to paint the material.
It will take several months for the steel to develop the rust-brown colour. The rust of the steel could stain adjoining surfaces, such as tiles and terraces. Corten steel and wet leaves, however, are not a good combination as the wet leaves delay the drying of the steel when wet. This increases the process of corrosion.
Stainless steel
Stainless steel is an alloy of mainly iron, chrome, nickel and carbon. The carbon percentage must be, at least, 11 to 12% before the steel can be classified as stainless steel. Many types of stainless steel could also contain the elements molybdenum, titanium, manganese, nitrogen and silicone. The stainless steel could discolour as a result of the heat of the fire.
The stainless steel
sparx outdoor fireplace is made of 304 steel, kgw Finish 28 (chrome nickel steel), which is the most common application.