the labor of love: polishing aluminum

[AngryScientist]

almost there...

http://2.bp.blogspot.com/-ZYVkr4UV8xo/UKlqjV8TEyI/AAAAAAAAA9U/-116j5HLjuc/s640/IMG_0333+(2).JPG

http://2.bp.blogspot.com/-Dgk8qR3V59Y/UKlqgXs5NWI/AAAAAAAAA9M/H9KY2-QeIfI/s640/IMG_0330.JPG

[kramnnim]

Was the original anodized finish marred by shoe rub, or...?

[DRietz]

No, true to his name AS got pissed at the molecules covering the cranks and decided to polish them off.

[54ny77]

ultegra 6600? nice work!

what was your process?

i've done it once before with a dremel...and that was a half dozen or so hours of hell (sandpaper grits of 800, 1200, then #0000 steel wool, then hours of simichrome and dremel buffing wheel).

my winter project will be a 6700 compact done much the same as yours, albeit this time in a proper workshop and an 8" buffing wheel (prior dremel polish job was on floor of an nyc apartment; this time will be in garage workshop).

[btl68]

Looks good. Gives it some life, some warmth.

Remember how alive old GT polished frames looked?

[eippo1]

Nice. Mothers or Blue Magic? I've done this to a few vintage parts like stems etc, but never a crank. That looks great.

[gone]

I've polished out a couple of cranks (a Dura Ace track crank and a 7800) and the fastest way that produces the best results (for me) is:

Start with a scotchbrite wheel on my drill press. This is fairly coarse but at a high RPM and using a light touch it takes the anodized finish off cleanly.
Move to a fairly fine grit wet/dry sandpaper - at least 400
Move to successively finer grits
Take out the Mothers Mag polish and finish 'em up

Takes about two hours start to finish working at it pretty hard. The result is a finish so shiny you can shave in it. I periodically touch it up with some Mothers, only takes a minute or two.

[AngryScientist]

I've polished out a couple of cranks (a Dura Ace track crank and a 7800) and the fastest way that produces the best results (for me) is:

Start with a scotchbrite wheel on my drill press. This is fairly coarse but at a high RPM and using a light touch it takes the anodized finish off cleanly.
Move to a fairly fine grit wet/dry sandpaper - at least 400
Move to successively finer grits
Take out the Mothers Mag polish and finish 'em up

Takes about two hours start to finish working at it pretty hard. The result is a finish so shiny you can shave in it. I periodically touch it up with some Mothers, only takes a minute or two.


This is almost exactly how i did it. Good summary.

[thegunner]

you going all alloy on a build nick?

[Hawker]

Looks great, I know this can be a tiresome process. And of course you'll always have to maintain it.

[Andrewlcox]

That looks great! I tried that on an old stem but ran out of elbow grease.

I once took an aluminum part off my motorcycle to a Kirby vacuum cleaner dealer where they had the biggest rag wheel I've ever seen. They loaded it up with rouge and turned my part into a super shiny part. The motor ran 3 belts to a shaft with 2 huge rag wheels. It took about 5 minutes.

[Louis]

Does bare polished AL stay polished, or does oxidation cause it to dull over time?

[thegunner]

Does bare polished AL stay polished, or does oxidation cause it to dull over time?

it should turn into the dull grey of aluminum oxide over time, but you COULD wax it (or clear coat it with something)

[Louis]

it should turn into the dull grey of aluminum oxide over time

That's what I thought. So if you remove the anodizing you either have to replace it with some other coating, or you're setting yourself up for a lifetime of polishing. (or, if you tire of that, a dull finish)

Sorry if it sounds like I'm raining on the parade. Just trying to understand the situation.

[54ny77]

louis once you strip the finish and go raw alu. all it takes is about 1 minute of a quick wipe with soft paste alu polish (mother's, simichrome, etc.) and a soft rag every month or so and it's as good as new.

think of it as same as polished alu. car rims that aren't clear coated. same issues in terms of getting dirty and so forth, w/same remedy.

[Louis]

Got it - subsequent polishings aren't as time-consuming as the one required to first remove the ano and various scratches. That makes more sense.

[john903]

I too like to polish up parts in winter it is hard work but fun and kind of theraputic and relaxing in a way and the end result is cool looking. Yes one has to touch it up from time to time but thats ok.

So a question to AngryScientist is have you ever tried removing the ugly black anodizing off hubs or spokes do you think I would lose strength in the spokes if i just sanded off the anodizing?
Have fun

[54ny77]

yeah it takes literally a minute. or maybe 3-4 if a lot of oxidation and surface scratches are present due to foul weather, etc. the nice thing about the raw finish is if you do have surface scratches (heel rub, for example), you can just buff 'em off.

Got it - subsequent polishings aren't as time-consuming as the one required to first remove the ano and various scratches. That makes more sense.

[AngryScientist]

john - i dont think removing any surface coating would ever effect the structural strength of metal parts.

re: upkeep - yea, i'll give them a good coat of automotive wax when i'm done, and that should last a good long while, i expect them to be easy to maintain shiny.

gunner: not a new build, i'm trying to rectify this situation:

http://4.bp.blogspot.com/-kkVlRKp2bN4/T8QJVrIvNoI/AAAAAAAAAec/KyGdWU8P6zI/s640/IMG_0750.JPG

[khjr]

I've read something about using oven cleaner to get the coating off before polishing on a buffing wheel - something about this chemical removal replacing the steps of sanding. Anyone know about that?

Was idly thinking about doing this to a NOS clearcoated/polished Ultegra 6500 front hub so that it would match my polished mid-1990s Campagnolo 8 spd rear hub.

[Hawker]

john - i dont think removing any surface coating would ever effect the structural strength of metal parts.

re: upkeep - yea, i'll give them a good coat of automotive wax when i'm done, and that should last a good long while, i expect them to be easy to maintain shiny.

gunner: not a new build, i'm trying to rectify this situation:

http://4.bp.blogspot.com/-kkVlRKp2bN4/T8QJVrIvNoI/AAAAAAAAAec/KyGdWU8P6zI/s640/IMG_0750.JPG

Angry...had to chuckle. Are those pieces of metal your next polishing project?

[guyintense]

I use easy-off oven cleaner as a first step but it has to contain lye and you have to wear thick rubber gloves. Then 320 alu oxide, then 400 silicon carbide wet, then Brown Tripoli, then Red Jeweler's Rouge.

[mhespenheide]

Has anyone tried the procedure outlined in this article (http://www.fixedgeargallery.com/articles/polishing/), which talks about the same basic polishing, but preceded by Jestco #780 anodizing remover? I've had the link bookmarked for a long time and may actually get around to trying it on an old set of cranks this winter.

http://www.fixedgeargallery.com/articles/polishing/


(AngryScientist: looks great!)

[fiamme red]

gunner: not a new build, i'm trying to rectify this situation:

http://4.bp.blogspot.com/-kkVlRKp2bN4/T8QJVrIvNoI/AAAAAAAAAec/KyGdWU8P6zI/s640/IMG_0750.JPGIs that Eagle Rock?

[shovelhd]

I use easy-off oven cleaner as a first step but it has to contain lye and you have to wear thick rubber gloves. Then 320 alu oxide, then 400 silicon carbide wet, then Brown Tripoli, then Red Jeweler's Rouge.

I use this stuff called Zam.

[Liberace]

Is that Eagle Rock?

Looks like it.

Hawker - The metal pieces are from the World Trade Center.

[Dave]

I worked in a plating/polishing shop for a couple of years ('71-'72). Aluminum is one of the easiest metals to polish, but having professional equipment makes the job take far less time.

Rough castings may need a lot of careful power sanding prior to buffing, but bike parts would only see a brief rough buffing with a sisal wheel and coarse compound before going over go a cotton buff and fine compound. The final step is usually done with a loose cotton wheel.

This website sell just about everything you'll ever need.

http://www.caswellplating.com/buffing-polishing/specialty-buffing-compounds/super-sisal-bar-compound-sc-18.html

What's in anodize remover? Apparently just sodium hydoxide.

http://www.eastwood.com/images/pdf/12582_anodize_remover_quart.pdf

[54ny77]

dave this is awesome link, thank you.



http://www.caswellplating.com/buffing-polishing/specialty-buffing-compounds/super-sisal-bar-compound-sc-18.html

[one60]

I agree with the Pro polishers comments above. If you have a nicely finished piece, the process is fast. If the surface has a shot peened(not smooth) finish you will expend great effort to even out that surface prior to polishing.

I found the jestco remover to be easier & more controllable than oven cleaner. One can adjust the strength & water temp to speed up the process. Try a scrap piece before taking your nice part to task. Its small but there is a learning curve.

[scooter]

OK, so is Ray Dobbin's advice/technique pretty much the drill for polishing aluminum? http://www.raydobbins.com/polishing/

[ultraman6970]

Remember somebody who polished a set of campy athena UT cranks and magically the logo was intact. Beautiful work.

[carlucci1106]

:p:hello:No, true to his name AS got pissed at the molecules covering the cranks and decided to polish them off.


My cranks are in the mail. NJ bound on a speedin' eastbound train

[zennmotion]

I agree with the Pro polishers comments above. If you have a nicely finished piece, the process is fast. If the surface has a shot peened(not smooth) finish you will expend great effort to even out that surface prior to polishing.

I found the jestco remover to be easier & more controllable than oven cleaner. One can adjust the strength & water temp to speed up the process. Try a scrap piece before taking your nice part to task. Its small but there is a learning curve.

The active ingredient is lye. I've done OK with oven cleaner as it's fairly weak in that form, but whatever you use put it on and don't let it sit too long until you have a feel for how fast it's working. Anodization is a porous aluminum oxide coating that's been dyed, the lye is a basic reduction solution. It will pit the underlying (pun intended) metal if left too long. The odors are toxic, and anything with lye in it is very caustic- it BURNS SKIN badly- long heavy duty nitrile gloves from the hardware store are a must as are safety goggles and expect a few holes in your clothing when you're finished. It's a mess. Be careful with seatposts as it's easy to take off too much and then they slip. I wouldn't do a stem for that reason, an unacceptable safety risk IMO. Lye, followed by fine-finer-superfine sandpaper, followed by Mother's Mag polish (see a autoparts store for that, works great) and then auto wax. A cotton rouge buffer wheel on an electric drill can speed things up.

[54ny77]

Hey Angry, i found a good old photo of a DA 7700 crank that i polished a few years ago with a lot of elbow grease and a dremel. It came out nice. Made a mess of our apartment though, that was not so nice...

http://i191.photobucket.com/albums/z113/jpmz06/Bike/P2180075_zps8e1b60c2.jpg



My BABM (that's Big Ass Buffing Machine) just arrived the other day along with various wheels and compounds, which should make things much easier for my winter polishing project: an Ultegra 6700 compact crank.

[monkeybanana86]

Hey Angry, i found a good old photo of a DA 7700 crank that i polished a few years ago with a lot of elbow grease and a dremel. It came out nice. Made a mess of our apartment though, that was not so nice...

http://i191.photobucket.com/albums/z113/jpmz06/Bike/P2180075_zps8e1b60c2.jpg



My BABM (that's Big Ass Buffing Machine) just arrived the other day along with various wheels and compounds, which should make things much easier for my winter polishing project: an Ultegra 6700 compact crank.

if you get bored I have a crank that needs a little polishing. seriously though, that crank looks nice!! any plans on polishing silver rings for it?

[54ny77]

i asked praxis if they'd make 'em silver and they said no.

if i can easily remove the black ano from ultegra rings and then polish without destroying the buffing wheels from the chainring teeth, i might tackle it. we'll see.

hoping to get to it this weekend, am building a mounting plate for the buffer itself so it doesn't move (8" buffing wheels, 3/4 hp, lotsa power).

[pcxmbfj]

Thanks.
I've got a set of DuraAce cranks I've worked on since 2007 so this may encouraged me to complete them.