Propane Locker Rust Stains

[sailcapt340]

Does anyone have any tips on removing rust stains from the bottom of the propane locker?
My steel propane tanks are rusting along the bottom rim and have caused some real rust stains on the bottom of the locker.
Thanks for the help.

 

[Stu Jackson]

If it's fiberglass, use FSR. Mary Kate's On & Off is similar and works well but is nasty stuff. Much nastier.