You may not believe it, but stainless steels ARE susceptible to rusting and corrosion. Stainless steels are alloyed with other metals such as chromium and nickel that form an invisible, “passive” film over the surface of the steel protecting it against corrosion. However, because this film is only millionths of an inch thick, there are everyday factors that can break down this protective layer and lead to rust.
Mechanical abrasion – items such as steel pads, wire brushes and scrapers will scratch the surface of stainless steel
Water – hard water may leave spots and when heated may leave behind deposits that, over time, will break down the passive layer of stainless steel
Chlorides – these harsh compounds are found in water, food and table salt and household and industrial cleaners
Steps to help prevent stainless steel rust:
- Use the proper tools
Always use non-abrasive cleaning tools. Soft cloths and plastic scouring pads are the best choices. Stainless steel pads can be used, but only if the scrubbing motion is in the same direction as the manufacturers’ polishing lines (see Step 2).
- Clean with the polish lines
Some stainless steels have a visible polishing line or “grain”. Always scrub parallel to these lines. If there is no visible grain, always use a soft cloth or plastic scouring pad.
- Use alkaline, alkaline chlorinated or non-chloride cleaners
If you are not sure of your cleaner’s content, check with your supplier. If your present cleaner contains chlorides, ask for an alternative. Also, avoid cleaners that contain quaternary salts, as they may cause pitting and rusting.
- Treat your water
Softening hard water can greatly reduce deposits. Installing filters is also helpful in removing deposits. Consult with a water treatment specialist if you are uncertain of the proper water treatment.
- Keep your food equipment clean
Avoid build-up of hard stubborn stains by cleaning frequently. Use the types of cleaners recommended in Step 3.
- Rinse, rinse and rinse again!
Rinse thoroughly and wipe dry, especially when using chlorinated cleaners. Wipe off standing water and allow equipment to air dry (the oxygen will help maintain the passive film on the stainless steel).
- Never use hydrochloric acid (muriatic acid) on stainless steel
- Regularly restore/passivate stainless steel
|routine cleaning||soap, ammonia, detergent, Medallion||apply w/cloth or sponge|
|fingerprints & smears||Arcal 20, Lac-O-Nu, Ecoshine||provides barrier film|
|stubborn stains & discoloration||Cameo, Talc, Zud, First Impression||rub parallel to grain|
|grease & fatty acids, blood, burnt-on foods||Easy-Off, De-Grease It, Oven Aid||excellent for removal|
|grease & oil||any good commercial detergent||apply w/sponge or cloth|
|restoration/passivation||Benefit, Super Sheen||follow product directions|
To learn more about chloride-stress corrosion and ways to help prevent it, contact your cleaning materials supplier.