All grades of stainless steel will require maintenance and cleaning to keep them in prime condition and prevent corrosion. Provided the grade and the surface finish are correctly selected, and cleaning schedules carried out on a regular basis, good performance and long service life are assured.
Many factors can affect stainless steel and the amount of maintenance it will require.
Atmosphere will have an effect on surface contamination and may cause deposits to form. These deposits may be minute particles of iron or rust from other sources used on the building. Industrial and even naturally occurring atmospheric conditions can produce corrosive deposits.
Certain working environments can produce more aggressive conditions e.g. hot humidity, such as in a swimming pool, and this in turn increases the speed of discolouration.
Modern processes use many cleaners, sterilizers and bleaches for hygienic purposes. All these proprietary solutions, when used in accordance with maker's instructions are safe if used correctly.
With care taken during fabrication and installation, cleaning before handing over to client should present no special problems, although more attention than normal may be required if the installation period has been prolonged. Where surface contamination is suspected, immediate attention to cleaning after site fixing will encourage a trouble free product. Food handling, pharmaceutical, aerospace and certain nuclear applications require extremely high levels of cleanliness applicable to each industry.
So how often should you clean? Clean the metal when it is dirty to restore its original appearance. This may vary from once to four times a year or once a day in hygienic or aggressive situations. Frequency and cost is lower with stainless steel than with many other materials and will often outweigh the initial higher cost of this superior product.
Stainless steel is easy to clean. Washing with soap or a mild detergent and warm water followed by a clean water rinse is usually quite adequate for domestic and architectural equipment. It is advised to dry the steel after cleaning to prevent watermarks and leaving any unwanted elements on the steel. If the stainless steel has become extremely dirty with signs of surface discolouration there are many other methods you can use to restore your product.
1) Routine Cleaning
Soap or mild detergent and water (such as fairy liquid). To avoid watermarks, use clean rinsing water, such as reasonable quality potable (tap) water and then wipe dry. Drying marks may be avoided using an air blower or wiping with disposable wipes.
Soap/warm water or organic solvent (e.g. Usher/Walker thinners No PF8017, acetone, alcohol) Then Rinse with clean water and wipe dry if necessary
3) Stubborn stains and discoloration
Mild cleaning solutions, i.e. CIF, Goddard Stainless Steel Care then rinse with clean water and wipe dry if necessary.
4) Scratches (Brush finish)
Polish with nylon abrasive pads. If wire brushes are used, these should be made of a similar or better grade of stainless steel. Ensure that all abrasive media used are free from sources of contamination, especially iron and chlorides. With directional brushed and polished finishes, align and blend the new "scratch pattern" with the original grain, checking that the resulting finish is aesthetically acceptable. Silicon carbide media may be used, especially for the final stages of finishing.
5) Oil & Grease Marks
Hydrocarbon solvents (WD40, methylated spirit, isopropyl alcohol or acetone) can be used to polish the steel. Alkaline formulations are also available with surfactant additions e.g. 'D7' polish.
*When cleaning a surface with any chemicals or abrasive medium, a trial should be done on a hidden or non-critical area of the surface, to check that the resulting finish matches the original.
*Chloride-containing solutions, including hydrochloric acid-based cleaning agents and hypochlorite bleaches can cause surface staining and pitting after long term use or soaking, and should not be used in contact with stainless steels. Similarly, common salt added during cooking or concentrated salt/vinegar mixtures may cause pitting over a period of time.
*Heavy hint tinting (oxidation) of stainless steel surfaces is unlikely to be encountered in normal use. Normally repeated cleaning with non-scratching creams should remove burn marks from stainless steel cookware, but in exceptional cases, (e.g. after a repair requiring welding or fire damage) it may be necessary to clean these areas using nitric acid- hydrofluoric acid pickling pastes or a nitric acid passivation solution.
Struggling with rust? View our guide to removing rust from stainless steel here