For outdoor works, such as facades, rain is generally good enough to clean off dust and other dirt, but it does so unevenly depending on its height and exposition. While performing the usual cleaning, a particular attention must be given to hidden areas to clean off accumulations of contamination agents found in the air. This is very important in marine and industrial environments, where heaps of chloride and Sox in the air may engender localized corrosion if it isn’t removed efficiently.
For indoor works, fingerprints may be something to worry about. There is a large range of special products for stainless steel and many of them work for largely exposed areas (where there is a lot of people). During the making of the product, the choice of surfaces less sensible to fingerprints may contribute to reduce the frequency and the cost of cleaning.
On mat finishes, often chosen for indoor, fingerprints may appear right after installation. These will disappear progressively after a few washes.
Cleaning Tools
A humid rag or chamois usually works to remove any normal dirt, fingerprints, etc.
For tougher stains, “scotch brite” sponges usually give good results. Ordinary metallic pads (steel wool), or metallic steel brushes are prohibited. It not only scratches the surface, it also risks contaminating the steel with iron particles which can lead to rusting when exposed to humidity.
Fine-grained polished products, like 180 brushed finishes and others must be polished in the polish’s direction.
After using water for washing or rinsing, the surface should be dried to avoid rings, mostly in some areas where the water is harder. The use of demineralised water will avoid these rings.
To avoid contamination with iron particles, make sure that the tools haven’t been previously used to clean “normal steel” (carbon steel). Materials used for cleaning stainless steel must strictly be used for it.
Cleaning Periodicity
Inside buildings, the periodicity for cleaning stainless steel elements is not different from any other materials. To reduce the costs and efforts for maintenance and to avoid damaging the surface, the cleaning must be done before any visible accumulation of dirt or fingerprints.
Outside, stainless steel is exposed to potentially more aggressive environments such as :
- marine environment,
- industrial environment,
- salt spreading,
- patina caused by air and traffic dirt.
These environments may cause the apparition of brown stains. We recommend cleaning these surfaces as frequently as the building’s windows. Depending on the amount of dirt and the importance of the deposits, it is suggested to clean the stainless every 6 to 12 months or every 3 to 6 months for heavier deposits described above. To eliminate such soiling, a stainless steel cleaning product containing phosphoric acid is recommended.
Cleaning Product
To erase fingerprints and other marks, the use of soapy water or a light detergent is usually efficient and safe.
Sprays are easy to use and cover the surface with a light film that gives it an extra shine. These products remove fingerprints and prevent them from reappearing. After application of these products, it is necessary to wipe the surface with a dry cloth.
“Mirror polished” stainless steels may be cleaned with window products if they do not contain chlorides.
For more stubborn stains, non-abrasive cleaning gels are efficient and should be also convenient to remove water traces and other colorations. After cleaning, the residues must be rinsed off with water (preferable demineralised water, as those sold for flatirons and for car batteries) and dried to avoid drips and water traces. Scrubbing powders should be avoided as they could scratch the surface.
Oil and grease stains may be removed with solvents like white spirit or acetone that won’t corrode the stainless steel. The solvent must not be poured directly onto the stain, it may be hard to completely remove it afterwards. It is recommended to use the product many times, to pour it onto a soft and clean rag until the dissolved oil or grease stain has disappeared.
Paint or graffiti must be treated with alkaline scouring for paint or solvent bases. Scrapers or knives are prohibited to avoid scratching the stainless steel surface.
Wrongly maintained surfaces may be treated with products used for chromed surfaces. Products used for polishing automobile paint may also be used. It is very important that these products don’t scratch finely polished surfaces.
Another solution is to use a product for stainless steel containing phosphoric acid, then to rinse with demineralised water, and to dry. To maintain a uniform aspect, this treatment must be done evenly on the surface.
Before beginning any cleaning operation, one must check if the supplier has given a safety slip and that it is well understood by the operator. Products not to be used on stainless steel are:
- Chlorine based products (such as hydrochloric acid),
- Bleaches
- Silverware cleaning products.
