Stainless steel is far from being truly without stains and is susceptible to rust. Rust stains occur because like all steel, stainless steel contains iron. When the protective chromium oxide coating that forms naturally on stainless steel is stripped away, the iron can rust. This happens when the steel comes into contact with bleach or is allowed to sit with salt or other corrosive food residue on it. Dishwasher detergents also can cause rust, and rust is more likely to form on knives than on other silverware pieces. This is because stainless steel knives use a carbon steel alloy, providing a sharper cutting edge but less rust protection. You can remove rust stains with several different cleaners and take steps to minimize rust in the future.
Nonabrasive commercial cleaning powders are excellent for removing rust stains from stainless steel flatware. Simply sprinkle some onto a damp sponge or soft plastic scouring pad and scrub the silverware with it, rinsing when you are finished. Bar Keepers Friend works particularly well on rusty flatware.
Pour some white vinegar onto a sponge or dish towel and wash the silverware in it for a rust-free shine. Thoroughly rinse the silverware when you are done.
There are two ways to remove rust with baking soda. The first is to create a paste. Mix one part baking soda to three parts water. Rub the paste onto the rust stains to remove them. If the stains are bad, apply the paste and let it sit for 15 or 30 minutes before wiping it away with a damp cloth. You also may make a paste that is equal parts baking soda and lemon juice. Use this paste the same way you would the baking soda and water mixture.
Because it's not environmentally friendly, lighter fluid should be your last option. It is, however, very effective for removing rust from stainless steel. Pour a little on a clean rag and wipe down rusting stainless steel. Be sure to rinse the flatware well after a lighter fluid treatment and properly dispose of the rag.
Turn off any stove burners before using lighter fluid and keep away from all ignition sources. Use in a well-ventilated area.
To prevent future rust stains, do not soak stainless steel silverware in water or allow it to sit in salty food residue. Rinse silverware thoroughly before placing it in the dishwasher, or hand wash and promptly dry the flatware.
Separate Your Knives
When washing stainless steel knives in the dishwasher, keep them separate from other utensils. Place them point down in their own area of the silverware basket. It also is wise to remove stainless steel flatware promptly when the dishwasher has finished to prevent the stainless from being exposed to the hot and humid dishwasher drying cycle.
Use Less Detergent
Try putting a little less detergent in your dishwasher when washing stainless steel utensils. Choose dishwasher detergents free of both lemon and chlorides.
When you notice stainless steel silverware becoming dull, give it a quick polish with stainless steel polish. This doesn't take long but cleans and adds a protective layer that helps prevent rust spots.