T Stew

I couldn't get the chainring I wanted for one of my projects in silver and ended up having to get black. I was going to live with it black but wondered if I could sand the anodizing off or use some kind of chemical and how hard that would be. I'd imagine bare aluminum would need polished every so often to keep looking nice, but on a classic build I'd much rather have a silver look to match the rest of the silver components. Will be going on a DA7800 (silver) crank upgrade for my '88 Tempo.

techsensei

You'd be better off painting it silver than trying to remove the anodized surface.

Kopsis

Some types of oven cleaner will strip anodizing. Other cleaning products containing oxylic acid (like Barkeepers Friend) will also work, but may require a huge amount of effort. If your time has any value at all, you'll be better off just buying silver chainrings.

Also note that even if you are successful, you'll be left with a bare aluminum surface that, even if polished, will tend to develop a cloudy, blotchy appearance as it oxidizes and passivates. It's unlikely to match the appearance of the clear anodized silver parts on your bike for very long.

tacoman1423

Concentrated grill cleaner will work

brianmcg123

Easy-Off oven cleaner. Spay on and let sit and bubble for half an hour. Do it outside as the fumes are toxic.

You will probably need to repeat it a few times to get it all off. But then once its off, you will have to polish the surface really well to remove any imperfections.

I did a stem once that was anodized black. Once I was finished with the oven cleaner, the stem had lots of imperfections in it that would not buff out. Anodizing covers lots of blemishes. I still use the stem today on my touring bike though.

Have fun.

Moe Zhoost

I've used a dilute solution of alkaline drain cleaner. The metal will turn black as the anodizing is eaten away. This washes off, but then you are in for a bunch of polishing. A good job for a rainy saturday.

T Stew

Thanks for the responses - sounds like a lot of work for sure and definitly something I'd only do if I had a lot of spare time, so likely won't happen but I'll keep these methods in mind.

I'd buy silver ones in a heartbeat - but like I said I was unable to find any. I admit I probably should have asked the forums help finding a silver one first though, someone might know something that I hadn't found yet. 130 BCD ~50t (or slightly less) narrow-wide chainring (10 speed compatible, for 10x1 road experiment) is what I am after.

blakcloud

Stripping anodizing is easy with drain cleaner. I have done stems and cranks and it was no work at all. Never tried a chainring but would like to just to see how it would work out. Maybe I was lucky as I started with good quality parts, White Industries ENO cranks and Cinelli stem and they buffed to a beautiful shine.

1989Pre 

Stronglight Dural 130mm Shimano 8/9/10 Chainring - Chainrings - Ribble Cycles

https://www.ribblecycles.co.uk/strong...-10-chainring/

T Stew

That does not appear to be a narrow-wide chainring at all.

Kopsis

Ah ... for NW you're probably out of luck on silver ano. Even in black, 50t NW is scarce. If you want to do this right, find an industrial anodizing shop that will do walk-in piece-part work. They can strip off the black ano and apply sliver/clear. It may cost a bit, but you won't risk screwing up the metallurgy with caustic chemicals.

Note that drain cleaner (a.k.a. lye, a.k.a. sodium hydroxide) will strip not only the oxide, but will also eat away at the aluminum itself. If there's any surface treatment on the chainring you risk losing it. Even if there isn't, you'll get lots of irregular surface pitting and erosion. Probably doesn't matter on something as robust as a stem or seatpost, but on tiny little chainring teeth that are under massive loads it "feels" risky.

Bill Kapaun

About 25 years ago, I anodized a limited amount of small parts. (Black)
If I had one that didn't turn out well, it went into a Nitric Acid dip for a few seconds to strip the black.
These were small parts that fit in a beaker. Think of 1" diameter cassette lock rings for a similarity.

DrIsotope

Depending on how deep the coloring is in the anno, you can often bake the color out. I've done it many, many times with aluminum parts of all colors. Try baking the chainring at a high temp (~450º) in a toaster oven for an hour or so. If the anno isn't deep, it will go to clear, if it is, it will end a sort of titanium/gunmetal color. If it ends the titanium color, you can always strip it afterward to get to the bare aluminum. Just know that the bare aluminum surface begins to oxidize immediately, so unless you like dull gray, the polishing process is never ending.

Bill Kapaun

And what does that do to the properties of the aluminum?
Aluminum Workshop: Achieving T6 designation for 6061 - TheFabricator.com

"....So we have a solid solution of magnesium, silicon, and other elements in aluminum at room temperature. This is called the T4 temper. If we take this material and heat treat it at a temperature between 325 and 400 degrees F, the alloying elements begin to form ordered arrays of atoms in the aluminum matrix. These arrays are called GP zones, and they strengthen the aluminum considerably. This heat treatment is called aging, which results in material with a T6 temper...."

SonsBikes

I've noticed that Evaporust takes anodizing off of some surfaces and leaves a bare metal finish.

fietsbob

TA makes Beautiful polished silver chainrings , you just dont look far enough . (or are willing to spend enough)

Lots of other 130 BCD chainrings are made by 3rd party suppliers .. Anodized with out adding a Color.

1989Pre 

You are right, T S. I replied without reading all the comments by O.P.

T Stew

No prob 1989, looks like fietsbob did the same thing.

I'm thinking staying black is more appealing then ever now! But I appreciate all the science and methods

I did ask WolfTooth if they would ever make thier Drop Stop chainring in silver in that size, and they said they had no plans to.

SloButWide 

This instructable claims that "Greased Lightning Cleaner" will do the trick. MSDS here - looks like it's a Sodium Hydroxide based cleaner, like oven & grill cleaners.

Jeff Wills

I just did that with a couple black aluminum fenders that I really wanted silver. They came out great, but it was a pricey proposition.

vettracer

[QUOTE=T Stew; someone might know something that I hadn't found yet. 130 BCD ~50t (or slightly less) narrow-wide chainring (10 speed compatible, for 10x1 road experiment) is what I am after.[/QUOTE]

I thought Wolf Tooth would make it, but interestingly, they make a 52T in 130 bcd, but not a 50T. In 110 BCD they do make a 50T, but I assume that you already have the 130 BCD crankset.

130 BCD Road / Cyclocross Chainrings ? wolftoothcomponents.com

T Stew

Well, not that it changes much but I was mistaken. The 50t is the one I am keeping black (I have two narrow-wide chainring projects), the one I'd prefer silver is 44t though I'd rather have something between the two in silver.

Here is what I got for my 1x10 projects:



The black on the 7800 crankset doesn't look to bad I guess. I'll wait for final judgment when it's all done and on my '88 Tempo but I don't think trying to DIY silver or having it done pro will be worth the hassle or cost.

I'd even do the 52t if they made it in silver, but the whole point of this is that they don't come in silver, in any road-ish size.

Camilo

I used Greased Lightening to strip the anodizing off two Shimano chain wheels, and it worked well. It definitely wasn't much of a hassle and I'm glad I did it. They were gray anodized, not black, but being Shimano I'm pretty sure it was good, tough anodizing so will probably be comparable to your black.

My opinion: do it - shiny silver will look better with the Dura Ace crank and I think you'll find it's not that hard to get it shiny silver.

I can't remember the exact procedure, but I just found it on the web (maybe even YouTube), and just followed the common directions people posted.

[edit] just looked at the above link, and that's probably the method I used.

I had to buy a gallon of the stuff (that's all they had at the Home Depot or wherever I found it locally... it wasn't expensive enough for me to justify looking around town for a smaller quantity). I used maybe a quart. According to the label, I will probably find another use for it sometime.

I followed that with polishing with metal polish I have on hand. I happen to have a buffing wheel (be careful or those teeth!), but you could hand polish it too. It looks great. Much better with the all shiny silver parts on a vintage bike.

fietsbob

Polish it off .