I read here that Naval Jelly is great on metals: http://www.hometalk.com/search?filter=rust&search=&zipcode=#!/179783
Navel jelly does help remove some rest, fine grit sand paper ( what ever count u want as long as low to high number. The good quality rustolium for out doo seal and pain sheen and color. Keep extra bottle and touch up one ever year or two. I have one also
And be sure to use treated wood if your going to add wood to your rack.