GravelMN

(Cross posted in C&V)

I've got an old 7-sp DuraAce triple that is in good shape mechanically but lacking aesthetically. It has a couple of wear spots through the anodizing and the logo is damaged on the diveside. The entire surface appears to have a haze in, not on, the surface. When I took a bit of regular mag wheel polish to them, the worn areas shined up nicely but the remainder still looks a bit milky. I want to use the crankset in a frankenbike project, so looks are secondary, but these look pretty bad.

What would happen if I removed the entire surface and polished what was underneath? I'm sure it would polish up nicely but how would I keep it that way? Protectant? Frequent polishing? or is it just a bad idea?

Thanks

wesmamyke

Almost any aluminum polish you could buy will have some protective stuff in it. I suppose straight polishing compound wouldn't protect the metal at all.

I have used nevr-dull on a stripped aluminum frame and it stays shiny for about a year. I would think keeping something small like a crankset shiny wouldn't be too much trouble. Depending on the weather you ride it in but you could probably just touch it up once a season or so.

zebede

If it were clear coat or paint I would say yes. As suggested these can be stripped and the aluminum polished to a mirror. I have done it several times. Anodizing is in the metal rather than on the metal.

Mr IGH

I'd use Eazy-Off oven cleaner to remove anodizing, then I'd polish it.

Matariki

Any product that contains sodium or potassium hydroxide will remove the anodizing. I generally use a solution of drain cleaner in water. As it works, the surface of the metal will turn black. This can be easily wiped off to check your progress. Once the anodizing is completely removed, you can then rinse and polish. A few precautions: 1) the solution is caustic so be sure to wear protective gear - gloves and eyewear especially. 2) Check progress frequently and stop as soon as the anodizing is gone. The solution will continue to eat away at the aluminum if you leave it in too long. 3) The polishing process may require you to use successively finer grits of wet-dry abrasive paper to get to a nice final polish. If you just try paste polish, you won't get the best finish.

Good luck.

fietsbob

I got a crank, (cheap) after someone ruined the surface doing that [Shimano M900]
if you want polish, start polishing , you cannot stop after that.


I'd just ride the bike and drop obsessing over the looks , try Dating instead.

shelbyfv

Posts 4 and 5 will lead you the right way. I like the EZ Off because you can use what you need and save the rest for another project. Be sure to get the heavy duty-not environmentally friendly variety. You can get fine grades of sand paper at auto parts stores. The whole process is easier than it sounds.

rmfnla

Once you finish the polishing using the suggestion of your choice give it a few coats of clear polyurethane to prevent oxidation.

You can use a matte finish to simulate the factory anodizing or glossy finish if you like the shiny look...

sch

Once you have cleaned up the anodizing as suggested, it is easy to reanodize with a sulfuric acid solution and a battery charger. Sulfuric acid is most easily
obtained as one of the drain cleaners, you just have to look at the labels. Perhaps 30 minutes to an hour would suffice. You do have to take care to fully
clean the metal and avoid finger prints eg use neoprene gloves to handle. It is quite easy and less dangerous than the oven cleaner used to remove the
anodizing. You can google how to anodize for details. A clear coat over this will protect it.

Kimmo

Once it's anodised?

I think you'd be better off dunking in hot water.