Polishing an aluminium stem

Discuss light weight issues concerning road bikes & parts.
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GASer
Posts: 229
Joined: Fri Jun 03, 2011 9:11 pm

by GASer

Hi, I am in the process of bleaching a Deda Zero 100 aluminum stem out of its gun metal factory paint. To do so I am using a P800 sandpaper and lots of patience.

You may see the result so far in the pics below. What I need to achieve here is a polished natural aluminum color that is not going to turn grey over time and match the color of this Deda RS01 seat post.

Any hints on the process, like polishing cream and/or clear coat, other? Thanks...



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Trek SpeedConcept 9.9 Project One, Basso Diamante SV, DeRosa SK (sold), Orbea Orca Gold 6430gr, Orbea Aqua, Tommasini Tecno, FM-066SL 6480gr, Kinesis RaceLight T2, Trek Superfly 100, Orbea Alma 29, Specialized Enduro S-Works 29, KTM EXC-250

by Weenie


latman
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Joined: Thu Aug 20, 2009 12:44 pm

by latman

thats the easy bit done !

fdegrove
Tubbie Guru
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Location: Belgium

by fdegrove

Hi,

You could have saved yourself a lot of time by using caustic soda instead of sanding it down.

Ciao, ;)
Being a snob is an expensive hobby.

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runner999
Posts: 326
Joined: Wed Jan 03, 2007 12:01 am
Location: Bay State

by runner999

1. Start with EASY-OFF® Heavy Duty Oven Cleaner in the yellow can to remove the anodizing finish:

Image

2. Spray the oven cleaner on and let it setup for 30 minutes, rinse off with water and repeat as needed though you may not need to seeing how much anodizing you've removed already.

3. Wet sand using 400->600 grit sandpaper to even the finish look to remove remaining black and logo markings.

4. Final polish with Mothers® Mag & Aluminum polish:

Image

Optional steps if you wish to forgo polishing regularly with above.

1. Clean part well with 90+% isopropyl alcohol.
2. Use a good quality automotive gloss clearcoat spray paint.

Good Luck! :beerchug:

Horacio
Posts: 216
Joined: Sat Jan 21, 2012 5:28 am

by Horacio

I would take it to a polishing shop, let them get it to look like a mirror and then take it to an Anodizer for a clear coat. The anodize serves 2 purposes. One for protection from sweat and the elements/dulling and the other from blinding you from the reflection of the sun. I'm not sure how that would match your seat post, but maybe have the seat post done in the same manner. It just depends how particular you are, but that's how I'd go about it.
Cost? Probably $100

User Name
Posts: 596
Joined: Tue Jun 07, 2005 3:32 pm

by User Name

Ray Dobbins is the master, and this is his 'polishing tips' page:
http://www.raydobbins.com/polishing/

I've done a few sets of Shimano cranks and chainrings; mostly older stuff (9sp),
but also one set of 7800 Dura-Ace.

Yes, Easy Off oven cleaner is much better, quicker and easier than sanding,
and it still might not be too late for you to try it. It may take a long time
to get the fine scratches out, assuming you've marked the aluminium under the
anodizing. If you have scratched the alu, I recommend gradually progressing
to the finest grade of sandpaper your patience can tolerate. Then, use an
electric buffer (or drill with buffing attachment) with (obviously) a buffer compound;
or skip the fine sanding, and try going straight to the buffer.
However, if the buffer compound isn't strong enough to remove the fine
scratches that may be there, you'll probably have to use fine sandpaper (I'm talking
1200, 1500, and maybe even 2000, all wet and dry). After a quick buff, I usually
polish hard with Brasso, then finish off with a chrome/metal polish, such as
Mothers or Meguiar's.

Before i found out about Easy Off, I sanded the first couple of crank-sets
I did, and it was painstaking. I spent hours in front of the tv with very
fine sandpaper, because I found it was more effective than the cheap buffing
compounds i had. Unfortunately, I wasn't able to remove all the fine
marks, but they still turned out pretty shiny, especially the 105 and
Ultegra 9sp

The last couple I did was with Easy Off. What I did was apply the
Easy Off; leave for about 10 mins; polish very hard with Brasso
(I don't have a good buffer); then finish with Mequiar's All Metal Polysh
(yes, the spell it with a 'y' :D).

I haven't bothered coating them, so i just give them a quick rub with
the Metal Polysh about once a month.

These are the 7800s that I did.
The photo makes them look a little shinier than they really are.

Image
Last edited by User Name on Fri Nov 09, 2012 4:22 am, edited 1 time in total.

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2002maniac
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Location: Utah, USA
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by 2002maniac

Just be careful not to leave the Easy-Off for too long. It will erode and pit the aluminum.

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prendrefeu
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by prendrefeu

Ummm... :roll:

I'll counter the previous comments and state: NEVER USE EASY OFF if it pits the aluminum after a while. That's a bit excessive, no?
Easier, safer solution: clean the anodized part in an ultrasonic cleaner with a degreaser (such as the environmentally friendly, citrus-based ZEP Heavy Duty Degreaser).

The anodization will leave completely. No damage to the part, no sandblasting needed, rinses off easy with water, no damage to the environment, no harsh chems, no feces from a bull.

Then proceed with your polishing.
Exp001 || Other projects in the works.

xrs2
Posts: 228
Joined: Mon Nov 07, 2011 5:46 am

by xrs2

Never thought of using degreaser, but looking at the material safety data sheet for Zep it doesn't seem to me it would be any less likely to pit aluminum than Easy Off.

http://hdsupplysolutions.com/wcsstore/B ... 113080.pdf

I've found that you have to leave easy off on for a very long time before pits form.

I like the idea of the ultrasonic cleaner though.

lechat
Posts: 260
Joined: Thu Sep 30, 2010 3:32 pm
Location: S.E. TN

by lechat

I wouldn't worry about using Lye, just as "natural" as citrus based solvents. Just use common sense.
+ it's a lot cheaper than an ultrasonic cleaner.

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SWijland
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by SWijland

Lye (strong one) didn't work for me. I tried dipping a couple of DA 7700 cranks in a strong lye solution, but unfortunately the anodizing came of anything but easily. Instead of leaving a dull surface it ate some parts much more than others.

Foo
Posts: 22
Joined: Thu Oct 06, 2011 6:33 am
Location: Sunshine Coast QLD

by Foo

Talcum power used with a microfibre or flannelette cloth will keep alloy nice and shiny and no chance of poisoning ones self. :idea:

Foo
So long as you have tried your best, then you should have no regrets!

by Weenie


User Name
Posts: 596
Joined: Tue Jun 07, 2005 3:32 pm

by User Name

SWijland wrote:Lye (strong one) didn't work for me. I tried dipping a
couple of DA 7700 cranks in a strong lye solution, but unfortunately the
anodizing came of anything but easily...

Ah yeah, I forgot to add: it's best to test the Easy Off on a small area,
because it doesn't 'agree' with some parts. I also did a set of 7700 cranks
that turned out crap, but another set turned out great. I also did an old
set of Record cranks (I think early '90s) that turned out crap, too.
The 7800 (above) turned out pretty good, but I couldn't prevent the logo coming off.
I've had best results with 9sp 105 and Ultegra.

Image

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