CLEANING STAINLESS STEEL
To properly clean stainless steel it is necessary to first determine what has to be removed and then select the appropriate cleaning procedure. Approaches to cleaning vary considerably; from those jobs that involve simple removal of dirt or smudges that collect on surfaces, to the most complex operations for removing free iron contamination.
Commercial metal cleaners may also be used, but it is important to make certain that they can be used on stainless steel and will not harm any of the surrounding environments. There are numerous cleaning compounds that are available. It is important to test the material that is being cleaned first to make sure that the cleaning compound does not adversely affect the stainless steel finish.
Below is a list of common mild contaminants, and methods for how to clean stainless steel for inks, oils, adhesives, and water scale:
- Dirt deposits on stainless steel including dust, dirt, fingermarks, and identification markings are easily removed. Frequently, warm or hot water with or without detergent is sufficient. Do not use carbon steel brushes or steel wool as they will leave particles embedded on the surface that will rust and stain the surface. For slightly more aggressive cleaning, use scouring powder with a small amount of vinegar. Rinsing in clean hot water should always follow cleaning. When water is known to contain mineral solids, which leave water spots, the surface must be dried with soft towels. Caution must be used so the towels do not pick up abrasives and scratch the surface. There are some cleaners and oil impregnated cloths that can also help avoid water spotting.
- Inks are typically removed by applying a solvent such as xylene or alcohol. Often the selection of the solvent is based on the type of ink and experimentation for removing and should be tested in an unexposed area if possible. Lastly, the cleaning should be followed by a thorough warm or hot water rinse.
- Oils can typically be removed using isopropyl alcohol or xylene. In cases where these solvents don’t work, acetone, methyl or ethyl alcohol, toluene, and mineral spirits will be more effective, but require some precautions. These solvents are flammable and may leave behind a residue. It is important to remove all of the contaminant and the residue by using a warm or hot water rinse or pressure spray. Furthermore, there are many over-the-counter cleaners that contain some of these solvents. It is important to try them in a limited and preferably unexposed area prior to any extensive cleaning.
- Adhesives are best removed using alcohol, xylene, or mineral spirits. It will often leave streaking; therefore, should be followed with a glass cleaner or similar cleaner that utilizes ammonia. If the adhesive is dry and not softening up with the mineral spirits, there are many cleaners in the marketplace that remove stubborn adhesives. It is important to try them in a limited and preferably unexposed area prior to any extensive cleaning.
- Water scale is best removed using vinegar followed with an ample amount of warm water. If that does not remove the scale, a mild abrasive may be required. Caution needs to be taken so that the material is not scratched contrary to the original finish on the stainless steel. Lastly, if the scale is persistent, a cleaner that contains a phosphoric acid or citric acid should remove the scale. It is important to follow the precautions for the cleaner and to flush the surface with warm water.
Each of the above contaminants are mild, and can be cleaned with these simple methods. Below are a listing of harsher contaminants which may require replacement if not mitigated.