Get yourself some micro mesh. It comes in 2400, 4000, 8000 & 12000 grit. It's also a cloth so it will wrap round the tube nicely. Works a treat. Then finish with novus. Otherwise your going to get swirly sanding marks all over it only going down to 600.
Of course this is only what I'd do.
You can get it on Amazon although I'm sure you can find it many places over there. I have seen drill attachments which will take the arm ache out of it.
Good luck.