Rust prevention

I love Ospho and have use it for years. Be careful. It needs to dry a day or two, before coating. It can react with some paints primers if not neutralized with water. ( ie: Sothern Urethanes epoxy they will tell you) Ii love it to get into the rusted pits, that no DA or wire cup can get to completely.
Like said the heavy Rusteolum works great for me to coat floors , underside, etc. It will not keep a gloss out in the weather for that long/