I have this pipe on my roof. I guess it's some sort of exhaust/ventilation pipe. As you can see it's (i) metal and (ii) rusty. What I want to do is (i) remove the rust and (ii) paint it Reasons for doing it is (i) aesthetics and (ii) I don't want the pipe to rust through and fall apart. Not sure whether it's likely in the next 5-10 year but since I live in a humid area I presume it might happen. Questions: 1. What type of chemical should I use to remove the rust? 2. What type of paint should I use? Thx!