Rust stains on stone coping

[Bart]

The builder left a piece of rebar on my stone coping and after some rain, there is a rust mark on the stone. Anyone have any ideas of how to get rid of this, or will it fade on its own?

Thanks!

 

[Bama Rambler]

Try undiluted lemon juice or vinegar and a stiff brush. If that doesn't work try some oxalic acid and a stiff brush.

 

[Bart]

THANKS! Will do.