Buddy of mine swears by Por-15. No need to paint over it.
Sent from my SM-G892A using Tapatalk
Sent from my SM-G892A using Tapatalk
Couldn't get anything from your link.
I've used Ospho. Chemically converts rust back to metal. DOES need to be primed/painted.
Ospho Rust Treatment - Since 1947
POR-15 is likely your best rust solution though.