Rust, POR15 and Corroless

[Chris.S.Mottram@ecc.com]

I am fixing some rust on the floor boards, trunk, etc.  I was thinking
about using POR15 or Corroless.  Is this basically the same stuff?  Where
can I find POR 15?  Am I better off just sanding/phosphoric acid to bare
metal then priming etc?  Should I use this stuff on the body panels?

Thanks,
Chris