Rust Converter and primer can be applied to any iron or steel surface to penetrate rust and turn it into a protective black coating. 

This protective coating will be resistant to moisture and prevents future rust growth.  Just remove any loose rust, then apply it like a primer to rusted surfaces.  Greatly reduces time spent wire brushing and sanding.  Durable and tough, it can be left as is, but is also compatible with most top coats.