# Removing anodizing



## doc_felixander (Mar 9, 2007)

I have to remove the anodizing from a piece of aluminium.
Not sure if it's Type II or III. ALthough it has a much more matte finish than the average typeII, it's less durable than HA. I assume it's type II.

I have to etch it away, as the piece has a pretty fine texture.
Is there any common household stuff that'll do the job, or will any rather weak lye (like concentrated detergent) just do fine?


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## 65535 (Mar 9, 2007)

I know that there are a some strong cleaners that remove anodization, can't remember what someone used though, check some RC or computer forums they sometimes remove anodizing from parts.


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## jtice (Mar 9, 2007)

I use Red Devil Lye powder.
Your local walmart should have it in the cleaning supplies.
Get about a cup of water and add about a teaspoon of Lye.
Soak part for a few minutes, you should start to see it bubble some, 
take part out, wipe it down with a wet rag, repeat as needed.

Dont make it Real strong, or leave it in Real long, it will eventually eat the AL.

I have also heard some stove cleaners work, but never tried it.

Do it outside, and wear gloves.

~John


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## gunga (Mar 9, 2007)

Oven cleaner works. I have done so on a few aluminum objects, have not tried a light yet...


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## randyo (Mar 9, 2007)

Greased Lightning works very well. I bought it at a local K-mart store and it stripped a couple of flashlight bodies fairly quickly.


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## doc_felixander (Mar 9, 2007)

Normally you can't buy too aggressive stuff in supermarkets in most European countries (except in France maybe)....I guess this is due to regulations here, as most people would probably simply flush it down the sink.

NaOH (e.g. Drano) would probably work, I think this is the most aggressive stuff you'll get around here (in a supermarket). 

For now, I'm trying with detergent (for normal washing machines), it's been boiling for 10 minutes now and the solution is turning grey....let's see what happens.

UPDATE: works fine. after 20 minutes, everything has come off.
MAybe it's not too good for the surface, but I didn't have to mess around with chemicals in my kitchen.


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## DaFABRICATA (Mar 9, 2007)

What light are you doing this to?
I wonder what anodizing will this work on


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## doc_felixander (Mar 10, 2007)

Don't worry, it was just a cheap Ultrafire and an aluminium part from my bicycle.

well, it worked. The anodizing on the Ultrafire was type II, I'm pretty sure now, but it was unusually matte. No idea about the bicycle part, as I've never knowingly seen type I so I probably won't be able to distinguish them.

Somehow I felt the urge to throw another flashlight into the pot (one of those cheap 12-LED-3xAAA-things with the glossy anodizing) just to see how it behaves. 
Eventually it came off too, but it took much longer, because of the less porous surface, I assume. 
The final result was worse than the first one, mainly because I forgot the pot on my kitchen stove once. All the water had evaporated, and everything inside was no more than a brown mess. 

Even this mild, not very caustic sulution (it's not much nastier than soap) did its job quite well. Even more than that, it etched away a thin layer of aluminium, so I have to reinforce the threads now.....although I have to admit that I threw in the part a few times in order to restore the finish after messing around with the surface. It stayed in there for about an hour, I guess.

When it comes right out the solution, the finish is pretty nice. It's a very matte shade of metallic white. Must be an oxide layer, but it's definitely much thicker than the oxide layer that forms when you cut or polish the surface. Moisture, from the hands for example, doesn't do anything, leaves no marks ot traces, nothing. It can't withstand much mechanical wear, though. 

As soon as I find a HA part, I'll repeat this nice little experiment and keep you updated.
Or maybe my HDS.....?!? I mean, who needs anodizing?


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## greenLED (Mar 10, 2007)

*the* anodizing removal reference thread on CPF:
http://candlepowerforums.com/vb/showthread.php?t=58899


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## LowTEC (Mar 10, 2007)

you mean something like this?






Just use Ez-Off oven cleaner for 30 minutes.


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## doc_felixander (Mar 10, 2007)

thanks, greenLED. didn't find that one. now i know what bookmarks are for.

@LowTEC: that's exactly what I meant. did you polish it afterwards?


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## LowTEC (Mar 10, 2007)

I was advised that I could polish it with plain cloth, but in fact, a dremel buffer along with some wheel polish did the job quick and easy


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## gunga (Mar 10, 2007)

LowTec, did you leave it one for 30 minutes? Can you outline what you actually did for the removal?

My LOP se is getting dinged up and I'm thinking of polishing it...


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## LowTEC (Mar 10, 2007)

gunga said:


> LowTec, did you leave it one for 30 minutes? Can you outline what you actually did for the removal?
> 
> My LOP se is getting dinged up and I'm thinking of polishing it...



As I said, spray the Ez-Off on for 30 minutes and rinse it good. My experience is that it might look kinda dark grey once you dried it off, I tried to spray it 4 more times but that doesn't change anything, so I realize the dark grey was actually the oxidization. I would say 30 minutes for once would be enough and then you can start polishing it, good luck!


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## Cuso (Mar 17, 2008)

Liquid-Plumer did the trick for me. Soaked for 30 minutes and that ano just fell right off... I have might do the treatment on my PEU pinapple and OptiqsHQ head if I dont find a suitable tailcap for it..


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## FsTop (Mar 17, 2008)

To avoid surface pitting, take it in stages: spray Ez-Off, use a nylon brush to get into the checkering, rinse after a couple of minutes, repeat.

I've had great results using a polishing cloth afterward. Here's an Arc AAA after two years of daily keychain carry.


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