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.

To paint a rusted iron railing, don't paint over the rust. Instead, use a material called phosphoric acid, sold by brand names such as Rust Reformer. The acid turns the rust black and makes it ...