chrisp

I bought a Cannondale Caad 2 frame that was anded to the bare aluminum. It was rough, so sanded it abit with some 600 grit sandpaper and that got it looking better. I don't intend to paint it, but here's the 3 questions I have:
1) What's the best way to get the surface of the aluminum super shiny-like a polish. I want to be able to do it myself with whatever I can find at the hardware store.
2) Will it all be for nothing if I don't clear coat it?
3) If I need to clear coat it, what is the best product to do it myself?

It's only going to be a commuter bike, so it doesn't have to lok too rad. But it'd be nice if it wasn't too ghetto either.
Thanks for your help.

psuaero

Not sure about bikes but a lot of "poser" guys polish the aluminum frames and wheels on their motorcycles. Same process probably goes for bikes, just keep going to finer and finer sandpaper, ultra fine wet sanding and finish with metal polish. You should be able to get it mirror smooth with a little time and effort. You have to keep with it or it gets dingy pretty quick. Probably not ideal for a commuter.

bbattle

Marine grade polyurethane. As many coats as you like.

Talewinds

I use a metal polish called MAAS, it's like a toothpaste consistency, works great on my aluminum frame mountain bike which requires a yearly polish.
Why did I buy a polished frame instead of the painted one?!?!?! I should have gotten the painted one.

DocRay

you really need a high speed polishing wheel and compound. The aluminum will corrode, so it needs to be sealed with wax or clear coat (ask automotive guys). I don't think polyurethane sticks to bare metal very well. Polishing the aluminum gives it strength.

Another idea is bead tumbling, it gives the ally a satin finish.

jrennie

If you want to give it a nice shine with minimal effort and expense then use Mothers Mag/Alum polish(you can get it at almost any car store)

TheDTrain

I use a bottle of spray on wax. It works on cars, so why not on bikes?

nova

Go with a supper fine brushed finish and clear it. Have the brush finish going with the tubes not around them. Once clear coated the bike will look like a silver pearl paint job from hell. I just seen a cdale caad 4 done up like this up close and personal. The effect is incredible.

chrisp

how finely does it have to be sanded before applying the alum. polish?

chrisp

So, you're saying to sand it with as fine a grade Sandaper as possible and clear coat it?

Nessism

Good luck finding a rattle can grade clear paint that will hold up to stone chips and the like common on bike frames.

SpongeDad

If you put a colored coat over polished Aluminum, do you get a colored mirror effect?

nova

Not a mirrored effect so much as a supper pearl apearance. Problem with mirror finishes with tinted clears is it tends to look blotchy. Best bet if your going to do a color tinted clear coat is a fine brushed finish. As fine as you can get before it turns to a mirror shine.

Ive seen aluminum bodied cars (very old vettes for example) done personaly my dad did a vette forget year. What he did was buffed the aluminum to a mirror then used ultra fine scotch bright to give it a very fine brushed finish then color tinted clear coated it. The effect was lets just say incredible.

Non titned clear over polished aluminum will give you a ncie mirror effect with out the blotchyness. It wont be a mirror though more like a supper high gloss finish.

Mark Dominck

I'm polishing a bare aluminum 979 Vitus road bike.I started with 1200 and then 3000 and now I'm finishing it off with 4000 pink polishing paper. It's looking pretty nice and I'm planning to just paste wax it and let it go and see how it holds up. I replaced all the old original scratched up components with some vintage Campagnolo Nuovo derailleurs, crankset, wheels and hubs with a brown seat and brown cork bar tape. I left the Weinman brake levers Tetro brakes,for now they both look pretty good with everything else and work good. I don't ride it very much just take it out for a spin once in a while. Like many of you I have quite a collection to choose from, I've had this bike sitting in the corner for many years and thought it would be fun to mess with, and I'm really glad I did it's been fun and looks good enough to hang on the wall.

Seattle Forrest

Is "polishing an aluminum frame" some kind of euphemism?

chaadster

Aluminum bodied Corvette? Uh...maybe you’re thinking of some other car? I don’t think there were ever any alu production Corvettes.

chaadster

OP, you only sand so far as to get to bare metal, then hit it with polishing compound and a high-speed buffing wheel to get the mirror.

As noted, it will oxidize and throw a dirty, dull top layer quickly, so you’ll want to get it clear anodized or suffer a life of never-ending maintenance hell.

Kimmo 

Nobody's noticed the sixteen year bump...

I stripped an ally frame to bare metal 25 yars ago, and I figured the easiest way to make it look good was hit it with some Scotchbrite to give it a brushed finish, which looked sweet. I figured I could just redo it if it got corroded or scratched.

After a few years of commuting on it, I realised the best finish was just to leave it - corrosion was very minimal, and it had acquired polished areas from me sitting on the top tube, and even under the front of the top headset cup, just from wheeling it around. Other areas had gradually attained a bit of a polish from repeated but less frequent contact too, it was pretty cool.

bruce19

If your dad did a Corvette he did a fiberglass body. I had a '66 coupe.

Kimmo 

@nova said that sixteen years ago.

Mark Dominck

I guess if you're reading between the lines you could make up some great stories about what I might mean but I was just trying to make conversation about my vintage bike project