I get the feeling that if the part is bad enough to need Evapo Rust, Cerakote is the least of your worries. Sounds like remove rust and then refinish would get you the best results.
Acetone will dissolve greases and oils but will not touch rust. If the rust got under the Cerakote, Evapo Rust will dissolve the rust and compromise the Cerakote bond to the object. A little contact could cause it to chip.
Acetone will dissolve greases and oils but will not touch rust. If the rust got under the Cerakote, Evapo Rust will dissolve the rust and compromise the Cerakote bond to the object. A little contact could cause it to chip.
Impossible for rust to "get under" Cerakote. Either it was there before it was coated- which is lack of prep and will need to be re-done after the Ckote starts peeling away- or it's a non-issue. As Baccarat said above, Ckote is completely solvent resistant- with Ckote having been correctly prepped/applied/cured, anything as inert as Evaporust (which you can safely handle without gloves) isn't going to affect it when the strongest solvents do not.
Evaporust is unlikely to effect the cerakote. Is this just a theoretical question, or a "asking for a friend" scenario? I'm genuinely curious as to the scenario that leads to a cerakoted rifle needing to be soaked in evaporust. Is the bore rusted?