I posted this in another section of the forum but I think more guys will see it in the technical section so here it is'
Rust removal can be SAFE and CHEAP and CLEAN. Do a Youtube search of rust removal using electrolysis and watch a few videos. Just remember do not use stainless steel for the sacrificial anode as that will produce TOXIC FUMES.
This flat out works and gets behind panels and inside blocks and otherwise inaccessible parts. Check it out. Pete