EvapoRust....?

[wee]

Anyone ever use this stuff to take the rust off the outside of a machine....?  It says it's safe on paint....I wonder if it work too slow to do much good. Directions say to immerse rusted object....No way to immerse the whole machine, the stuff is too expensive.

I have seen the results with Rustmort which if what I read is correct is just phosphoric acid diluted with water....Just not sure what %

Brian