Rust on Boiler Tube

[Endlesssummer]

We have a 15 year old Dometic RM 2652. The boiler tube where it leaves the flue pipe housing above has rust on it. We do a lot of beach camping and maybe the salt in the air has caused this to happened as it’s near the upper side vent. It’s a little more than just surface rust.
Question: Has anyone applied a rust inhibitor to slow down this deterioration?
Thanks

[VA-Apraisr]

My RV has been on the beach for 17 years and the refrigerator tubing is totally rusted but still working. I occasionally have to tap it lightly with a hammer/screwdriver to keep upflow for flame moving into the tube, but otherwise, it just keeps running.

[midnightsadie]

live in ohio,my tube has rust ,I just leave it alone gets pretty hot in there.