Rust free rust belt heeps can be found...
I bought mine in west Pennsyltucky and the P.O. has sprayed this awful nasty sticky undercoating everywhere. It is the bane of my existence. Every time I work on it I come out looking like I just went exploring a sewer. My tools are so gunked up I don’t bother putting them away. I have clothes I only use for working on the Jeep.
But... it worked. Everywhere it covered there is no rust to be found. Body mount bolts, shock bolts, pumped bolts all turn like butter. Paint looks brand new under the goop. Places where it was missed did rust, but those areas are small and few. So I’ve taken to applying fluid film every time I have to clean some off to work on it.