Polishing alu - help needed

[jalabert]

Hi<br /><br />My Dura Ace pedalarms(not sure what they are actually called) has taken quit a beating and look very bad. For this reason I was planning on polishing them, but I'm not quit sure how? They are anodised which will have to come of first, but how do I do that?<br /><br />Any advice will be mucho appriciated

 

[Duckwah]

if your cranks are anodised you will find it very hard to polish them by hand. Anodising works by enhancing the natural layer of aluminium oxide on the surface of the metal. <br /><br />Aluminium oxide is also the second hardest substance on earth which means you will probably have to get an auto repair shop to sand blast them before you try and polish them.<br /><br />i would suggest that you find an auto shop that will sand blast, polish and clear coat them to save yourself the hassle of trying to do it yourself.

 

[jalabert]

Thx for the reply<br /><br />Turned out not to be anodised after all eventhough it say so on the Shimano website. It comes right of with 150 sandpaper so I shouldn't have any problem doing it myself. Should it turnout ok I'll be sure to post an &quot;after&quot; picture, but it won't be for next couple of weeks since I'm currently studying for finals which sucks &gt;

 

[James Godley]

Jalabert!

Autosol everytime, long as it's directly onto the metal. Its an abrasive cream that after some polishing will bring the metal to a beautiful shine. I often apply to my cranks. Beware, it actually removes a microscopic layer of metal!!!

 

[jalabert]

As the season for the summer bikes are approaching I have finally finished my project of polishing my crank arms. The result is pretty good, but could perhaps have been even better, but I have had enough Anyway I'm sure they going to look great when mounted since I then rarely will look at them up close as I have been doing while working on them.

Cheers
I added the before picture again as I see it was lost when changing to the new forum.

 

[Lazy legs]

jalabert, great job!

Tell me when I can send you mine. Only thing is you won't have 2 months to finnish mine.

 

[steve]

Originally posted by jalabert
As the season for the summer bikes are approaching I have finally finished my project of polishing my crank arms. The result is pretty good, but could perhaps have been even better, but I have had enough Anyway I'm sure they going to look great when mounted since I then rarely will look at them up close as I have been doing while working on them.

Awesome....they look better than new ones

 

[jalabert]

Originally posted by Lazy legs
jalabert, great job!

Tell me when I can send you mine. Only thing is you won't have 2 months to finnish mine.

Thx! I'm also pretty happy about the result, but still I must say: NEVER AGAIN

And, yes they do actually look better than new(I think). I have never seen such a pair up close, but I geuss they look like the "25th birthday edition version" which is also handpolished.

 

[dexmax]

how did you do that again?

I have an old sakae svx cranks that needs to be polished too. I have used dozens of products -- autosol, and othe metal polishes...

did you sand it before you polished?

how long did it take you to do it?

did you spray top/clear coat after polishing?

thanks...

 

[jalabert]

I used the following sandpaper 150, 240, 400, 600, 1000. Unless there are some very deep scrathes in it you can probably skip the 150. Be sure to be VERY thorough with each of the different types of sandpaper, otherwise you will leave scrathes in the surface that can't be polished away at the end. After the sandpaper I used Autosol and finally Slipol(if you know that!?). I haven't done anything to the surface so I'm looking forward to seing how long they stay shiny and mirrorlike.
I did it all by hand so all together I think it took about 10 hours(yeah, I know I don't have a life). I geuss you can do much of the work with some kind of fancy rotating modern machinery. However to get the best finish the final polishing will have to be done by hand.

Good luck ;-)

 

[Frejus]

Originally posted by James Godley
Jalabert!

Autosol everytime, long as it's directly onto the metal. Its an abrasive cream that after some polishing will bring the metal to a beautiful shine. I often apply to my cranks. Beware, it actually removes a microscopic layer of metal!!!

Yes its great stuff I have used for years, on a wheel buff you can actually get a better shine than anodising which is a clear electro plate system.

The also is a buff stick which does the same job but a little softer.

 

[jalabert]

Autosol is indeed great, but the alu used for these shimano cranks are so soft that the autosol makes visable scrathes in the surface. If you are very carefull to only polish in one direction the result can be okay, but the result will only be perfect if you after Autosol use another type polishingsolutionmixturepotion. For thes I use Slipol but I don't know if these is a worldknown brand?