I didn't get it from Harbor Freight, but I used Evapo Rust and was very happy with it. I have an old engine that had some rust, but had never been painted, and still has the factory Ink Pen markings. It cleans all the rust, leaves it a natural cast color, and never disturbed the Ink Marks. works nice if you have some cad plated pieces that need cleaned up. Also, not toxic.
