Q: Thank you so much for your article on rust and oxalic acid ("Rust isn't her best color," Jan. 7). We have had this problem for years! And it is frustrating. We even have our water treated through ...

Q. I have a nice-looking terrazzo floor that has rust spots made by paint cans left on it. I tried removing the rust with Rust Reformer and a little bleach rubbed with steel wool, but nothing worked.

Q: My concrete sidewalk and driveway have large brown rust stains that I haven’t been able to remove. I tried bleach and a chemical remover to no avail. Can you help? A: Rust stains on concrete seem ...