Thanks for sharing your results Paul.
The 10% phosphoric acid solution will remove the rust, given more time to work, without the loss of good metal.
When applied to sheet metal, if you cover with plastic wrap, the acid solution will have more time to work on the surface without drying out.
If the acid/rust solution does dry on the surface, wetting again with solution and scrubbing with scotch brite pad will remove the residue. When the metal is derusted and clean, spray on the acid solution and dry the surface. The metal can be stored for an extended period without rusting IF the metal is not exposed to moisture or bare hands.
