Stains in cast iron tub

[Michael Shadow]

Ok we started to clean out an old cast iron tub and doused it with bleach and well after working on it for some time the bleach made all of these rust stains appear. How do you get rid of them? I tried scrubbing with lime-away which seemed to be slowly removing the stains but there are still some that it didn't cut through yet.

Any ideas?

Also is there any product to coat the inside of the tub to make it look new again or to put a sealer on it so it's easier to clean.

Thanks,

-Michael