Acid gets rid of rust. Any mild acid like vinigar, or a grout/concrete cleaner containing phosphoric acid will do. Obviously caution is needed so you don't damage the OPT or yourself. It's then a case of giving it a good wash and then applying something to prevent further rust.
There are commercially available rust treatments but their ingredients are basically acid + X .
Andy.
There are commercially available rust treatments but their ingredients are basically acid + X .
Andy.
