Limiting The Rust

When we brought our trailer home last week to get it ready for a weekend camping trip, I noticed "once again" that rust had developed on the Bargman door handle, as well as the 3 hinges used to attach the screen door. I plan to take the steel wool to the rust, but was wondering if there is some clear coat product that could be applied to prevent the rust from returning, or at least keep it to a minimum? Seems like there's always some maintenance that needs done with these relics.

Thanks for any advice!

Dan