Bob Vila explains how to get rid of the rust in a sink.
Kohler product can't rust on its own.A metallic particulate oxidizes on the surface of a product and turns it to rust.Rust can be found on the top surface of a product.Glass, cast iron, and other materials can't rust on their own.Rust isn't the result of a manufacturing process or a defect in the product.
When rust appears, it is usually only surface rust and can be easily removed with the right cleaners.Don't use steel wool, wire brushes or abrasive sponge pads.Non-scratch cleaning pads are used.
You can find more information about Kohler products on the Care & Cleaning site.
If there is rust on the inside of your sink, it is most likely the result of the chemicals being used in the sink.Don't use bleach to clean counter tops next to the sink because it can cause rusting.After using the counter top cleaner, rinse the sink.
If there is rust on the underside of the sink, it is most likely due to the cabinets contents.Fumes from household chemicals can rust a sink.Do not keep open containers of cleaning products under your sink.