Rust stains in your sink may be brought on by standing water in which it comes from contact with metal items or by a split in the sink in which water seeps in. These red-orange stains may occur in a stainless steel or porcelain cast-iron sink, but you may use the same cleaning methods on any type of sink. Keep the sink dry if it’s not being used and avoid putting metal objects directly in or on the sink to stop new rust stains.
Dampen the rusty areas of the sink with water.
Sprinkle the rust stains using a light layer of baking soda. Apply several drops of vinegar into the boiling soda. Scrub the stains with a damp cloth or nonabrasive scrubbing sponge to remove the rust.
Wash the sink thoroughly to remove any cleaning residue.
Sprinkle a light layer of oxalic acid-based cleaning powder into some remaining rust stains. Wipe the stains with a damp cloth to remove them.
Wash the sink with water and dry it with a towel.