how to prevent aluminium corrosion

I've got a set of aluminium handlebars which just keeps corroding. I can polish it up very nicely, to almost a mirror finish. But then within maybe two days (!!!) the whole thing will turn dull and white again. Is there something I can do to keep this from happening?

is it stored in a cold damp shed?

best thing to do is once polished protect it with some kind of wax. i dont know a cost effective solution but i use rimwax on my car wheels as they have polished alloy lips.

It's currently stored in the carport under the house so it's protected from the most severe weather influences but it is cold and damp out there. However, the bike does have other aluminium parts which I also polished, and those parts are still shiny and they don't corrode nearly as fast so maybe it's got something to do with the grade or type of aluminium? Thanks for the reply though, I'll have a look at Halfords to see if they have some kind of rimwax!

Have you tried Boeshield T9?

or Zoopseal - protects against corrosion for a couple of years before it needs re-application

I haven't tried anything yet, I've only repolished the bars a couple of times hoping the corrosion would stay away but it didn't, and I've been wondering why the handlebars are so sensitive to corrosion while the other aluminium parts are not (they're not snodised either). But now I guess the time has come to try something that actually might work I'll see if I can find any of the mentioned products, thanks!

My local jeweller who races motorbikes swears by Pantene - it has silicon in it and works really well. Just use it like a polish!

Car wax or similar should keep it shiny for months after you've polished bare aluminium with a metal polish.

I think a metal polish like Autosol has some wax in it already, but perhaps the grinding action of the polish doesn't leave much wax on the newly polished surface, so giving it a good waxing should keep it shiny longer. But still, whenever I've polished an alu part with just the metal polish, it doesn't go dull within a few days.

I wouldn't say it's corrosion either. A bare aluminium surface will react with oxygen to form a very thin oxide layer, but the oxide will stop any further reaction. Anodising is just a thicker oxide layer applied by the manufacturer. Damaging corrosion is usually caused by salty water, either from road salt or sweat, it will eat away aluminium, both unanodised and anodised, by turning it into a white powder.

Hmm thanks for the input! The bike isn't exposed to salt, I don't live near the sea and it's hard to imagine the previous owner sweating so much the entire handlebars start to turn white by the ammounts of salty sweat that gets poured over them!
Anyway I bought an aerosol can of auto wax today (much cheaper than I expected at only €2,-) which supposedly protects painted surfaces, copper, silver, chrome, marble, artificial leather, and plastics from UV rays and chemical influences. Let's hope it also works on aluminium and corrosion or oxidation can be considered a chemical influence I'll keep you posted on whether it works, if it doesn't Pantene might be worth a shot.