Rust remover?

It works good but you have to keep it wet for long periods. If you are doing stuff that is large it's a pain and the more expensive store bought manufactured stuff will work better (faster and easier) than the vinegar.
If you are home all day to do it you can respray every half hour or so.
It is natures anti-rust. Grab something rusty and put some on it. It wipes flash surface rust right off and works good on old chrome if you wax it afterwards.