Stainless Steel offers a high level of protection against the elements and some grades of Stainless Steel (such as 316 Marine Grade) are suited to coastal environments. However, it is critical to note that all Stainless Steel fittings must be properly prepared BEFORE installation, and maintained regularly, in order to maintain their finish.
Stainless Steel has a very high resistance to corrosion. Despite this, ‘blotches’ may appear on the surface of the stainless steel. The cause of the blotching is due to some free iron atoms from the polishing wire brushes remaining on the surface, and is NOT A FAULT. A soft cloth soaked with neutral oil (WD-40) should remove these ‘blotches’.
If exposed to very corrosive environmental conditions (coastal areas, salty atmosphere etc) Stainless Steel will require additional maintenance. BEFORE installation, the stainless steel parts MUST BE TREATED with neutral oil, which must penetrate all the joints, after which, dry the area with a soft cloth. In extremely corrosive environments, the treatment with oil must be repeated at least 4 times a year. In case of serious corrosion, use an abrasive paste designed for stainless steel to remove the stain, then reapply the neutral oil again.