If anyone is interested. This is a great product. It is water-based and I have used it several times. It turns the rust black and hardens the spot. Easy to use and enviromentally safe.
The product of extensive research, EVAPO-RUST is an environmentally safe water-based rust remover that has been proven to make even deep rust disappear in minutes, without scrubbing. EVAPO-RUST is easy to use--anyone can restore their rusted steel tools and auto parts to like-new condition. EVAPO-RUST will not harm metals, rubber, plastic, PVC, VitonĀ®, most paints, or un-rusted steel. Best of all, EVAPO-RUST is safe to use and is biodegradable. It's nontoxic, non-corrosive, nonflammable, and contains no acids, alkalis, or petroleum solvents.
Available at Summit Racing and O'Reilly Auto Parts