How to Remove Rust From Metal Shed Roof

[Philip Nowak]

Hi BP Community, anyone have any tips or experience removing rust from a metal shed roof? 

I tried TSP as well as Naval Jelly, letting them sit for the appropriate time in the recommended application temperature range. I then scrubbed the roof vigorously with a nylon bristle brush and a metal bristle brush.

Nothing helped beyond some light surface rust as well as making the unaffected areas appear cleaner. After 2 hours of rinse and repeat, I packed everything up and called it a day.

I don't know how old the shed is or what kind of metal it is as I just purchased the property in 2013. The shed is about 13 feet by 21 feet. What's interesting is that the inside of the shed roof is in pristine condition with no penetration of the rust from the outside...yet.

My goal is to preserve the shed from further deterioration. My options are to replace the roof or remove the rust, prime, and paint. I'm apprehensive about trying to sand it with a power sander as the roof has an uneven texture on it. Any ideas?

Thanks,

Phil