STAINLESS STEEL DURABILITY
Common stainless steels in lighting are 304 and 316. Generally speaking 316 is the desired standard as it has the best resistance to corrosion. Although 316 is usually regarded as the standard “marine grade”, it is not resistant to the chloride that is naturally in the air. In many environments 316 does exhibit surface discolouration in the form of tea-staining. This looks similar to light rust – in fact customers will argue that it is rust – but it actually polishes off with vigorous rubbing. This is the natural characteristic of stainless, and occurs with all stainless products in all environments. As chloride is more prevalent near the sea, the performance of stainless is also more of an issue in marine environments Tea staining, although aesthetically not ideal, is not a serious form of corrosion, and in general does not affect the structural integrity of the material. The superior performance of 316 stainless has a lot to do with the percentage of molybdenum added to the raw material, as well as the smoothness of the stainless surface. The 316 stainless used in mid-priced outdoor lighting is clearly at the lower end of the 316 scale, and is not comparable to the highly expensive marine grade products used in the boating industry. The only way to minimise tea staining is to maintain the product, or apply a protective coating. Any coating must be UV resistant, therefore all local hardware lacquers are not an option. Interestingly, stainless exposed to rain performs much better as the rain tends to wash off the chloride. At the moment the stainless look is all the rage, so in order to ensure we can provide products that are suitable to our conditions, we offer many of our stainless products with a clear powder-coat protective layer. We also offer other options such as brushed-aluminium and brushed-chrome, both of which are similar in appearance to stainless, but are far more durable and resistant to rust and staining. Even these two finishes we clear coat to ensure satisfactory performance. Raw unprotected stainless is still a popular option, as it does have a more natural metallic look than the slightly glossy clear coated option. Also, it is fair to say that some of the more upmarket European lighting available will perform better, simply due to better quality stainless material. Generally, stainless in an unprotected form, requires maintenance! You will note on super-yachts, they are for ever polishing away. Reason being, they are dealing with stainless steel. Until stainless goes out of vogue, it is important that end users are informed of the performance of the product, and also the other options available.