Here's how to remove rust stains from sinks:
1) Thoroughly clean the sink or stainless steel area with BRASSO® MULTI-PURPOSE METAL POLISH or BAR KEEPERS FRIEND®. Pay special attention to the stained area.
2) It is important to remove all debris to prevent the stain from reappearing. In some cases, you may need to use a soft nylon brush.
3) Make sure to clean and brush with the grain of the steel, i.e., the lines that appear on the sink inside the bowls or on the deck.
Rust should not return once correctly removed. If you continue to see rust stains, contact the place of purchase or the sink manufacturer for further assistance.