How do you clean RUST stains in a sink?

Use C.L.R. You might have to do it a few times.

Good Luck

ZUD is the best thing I have seen that works on rust stains. It is kinda like comet and is an abrasive cleanser but seems to work alot better on rust stains, even old ones. I have cleaned alot of old houses and done renovations and it always worked well

Barkeepers Friend works wonderfully! We use it regularly at my parents house, because they have bad rust in their water. You can sprinkle it on like Comet or Ajax, or even better is if you make a paste out of it and put it on and let it sit for a few minutes. It takes very little elbow grease if you do it this way! Good luck with your question!

White vinegar and baking soda is good for rust stains and will not scratch the sink.