Rust remover dissolves the rust by chemical action. Needs to be washed thoroughly before painting.
Rust encapsulator is a bit of a misnomer, it’s actually a rust converter that stabilizes the rust by converting it a different form of iron.
There may be a rust “encapsulator” out there but I’m not familiar with it.
https://www.theruststore.com/Rust-Co...-FAQs-W48.aspx
EDIT:Yes, there is a rust encapsultor, so you have 3 choices...
https://www.eastwood.com/eastwood-bl...over-rust.html