Framebuilders - removing aluminum frame paintm corrossion?

http://img246.imageshack.us/img246/9242/bikezl4.jpg
so i just helped my friend get this bike, aluminum frame, 28" wheels, really nice ride! rode it about 80 miles in Mexico City today.
so the only thing my friend doesnt like about it are the decals. they are painted on there pretty good, he wants to just sand them off. is it safe to leave aluminum bare? i guess we could just rattle can it after, but he sais "just make it look old" !!!
http://img246.imageshack.us/img246/9242/bikezl4.jpg
By chiapasfixed (http://profile.imageshack.us/user/chiapasfixed), shot with KODAK Z730 ZOOM DIGITAL CAMERA (http://profile.imageshack.us/camerabuy.php?model=KODAK+Z730+ZOOM+DIGITAL+CAMERA&make=EASTMAN+KODAK+COMPANY) at 2008-01-15

If the graphis are painted on you'll have to sand them off, that'll ruin the paint job and you'll need to refinish the whole thing. If they're only decals you can use a heat gun so soften them up and slowly peel them off. Use alcohol and a soft rag to remove the glue residue.
Good luck

If its paint I can make what ever graphics you want to cover up the benotto paint scheme. Even just plain blue to match. No sanding or teardown required with a pro finish

cool, but you are in portland oregon, and the bike is in mexico city....
care to tell me how you do it?

You can get them to come off with a less abrasive method of removal than sanding. Take a medium or coarse Scotch Brite and a bucket of water. It is important to have the water or else it can get ugly. Only use enough effort to get through the decal or clear on top of it, then peel what you can. When it is clean of the decals, then you have 2 options, depending on the condition. Either wax and have it be what it is, wax will make it glossy again. Or clearcoat/or add decals of choice with clear on top of them. Ive had good success with both in the past.

Yes, it is safe to leave aluminum bare. It will look pretty bad in the beginning, and much worse after a year or so, but I've never seen a bare aluminum frame fail. But seriously, if your friend thinks the frame looks bad now, he should see it after the paint has been removed and the metal has oxidized. Unless he's a big fan of Mad Max, he should probably leave it alone.

¿Aluminum bufalo? Chiapas, I can`t offer much advice about your question, but I wanted to comment on your buddy`s bike- I like it! I`ve spent a good amount of time trying to track one down (the older steel framed ones with rod brakes) but finally decided that every single one was going to be WAY to big for me. Good luck with it, I hope he enjoys rolling over the volchos with those big old 28-inch tires! The one little thing I could say is that, if he decides to do any repainting or needs local service, there`s a good forum here:
http://forums.mtbr.com/forumdisplay.php?f=113
Most of the posters are there in Chilangolandia and could give specific suggestions about painters or whatever.

To add to the line about never seeing a bare frame fail:
In tubing inspection, the first rule of thumb is that a clean polished frame hides no secrets. Paint does.

My friend had a polished aluminum frame crack, but he knew about it loooong before it was a problem because it was polished, so it didnt bite him.