Tips on destroying or decaying an anodized finish?

[prendrefeu]

I've tried a bit of searching and was unable to find anything definitive. I'm wondering if any of the experts on WW, maybe a few from the industry, can offer a few tips.

I would like to decay/destroy an anodized finish on aluminum. This isn't removing the anodized finish completely, but decaying it/destructing it so it no longer looks clean and attractive. I would like it to look the opposite of clean/attractive, which would be closer to dirty/unattractive. Ideally, I want the end result to look terrible and corroded, but still have a relative reliability that the finish will not decay further past the point in which I can stop it (if that is possible?) and it won't 'rub off' on clothes or other components when the part is actually put to use.

Any help on this would be appreciated. I'm hoping to make this a DIY/home project, so any materials or techniques that can be done "in the home" would be ideal.

Thank you in advance for your help on this.

[Frankie - B]

I know of a few degreasers that could do that. Very popular in Holland is Dasty kitchen cleaner, it is dirt cheap, but eats almost everything. muc off is a good candidate as well. I guess that that is because there is lye in it.

[moman]

Caustic Soda or get a Rotary Wire brush thing for your drill?

We anodise at work, getting it stripped to halfway would take a lot of guess work and is generally not done. You would need to know the thickness in microns of the coating to time the striping process. If you do use caustic soda dont soak it just rub it, depending on the alloy you could end up with a sieve otherwise...

[kbbpll]

Is this like distressing furniture? Whack it with a dirty old chain and then rub it with mineral spirits on a greasy rag.

[KB]

Oven cleaner's good for taking off anodising, but taking it to distressed would be difficult.

[dj97223]

Tape over all of the logo's with electrical tape so it looks like a stolen bike. Add hipster hair, tats and colored rims, and you're good to go.

[Camilo]

If you want to uglify it without affecting strength, why not just take some similar color (black, dark gray, gray, etc.) spray paint and just randomly spray it a little to make it look similar but splotchy and ugly. Then, later if you wanted to restore it to nice, you could probably remove the paint without ruining the original anodizing.

If you really want to permanently 'distress' it, have you tried just taking some sandpaper to it?

[prendrefeu]

Sandpaper will probably be used, but adding paint is no-go: I don't want to add unnecessary weight to produce an effect.

[Camilo]

Sandpaper will probably be used, but adding paint is no-go: I don't want to add unnecessary weight to produce an effect.

[tranzformer]

Prend, sounds interesting. Do you have a picture showing what you are looking for/expecting it to look like at the end?

[LouisN]

Sandpaper will probably be used, but adding paint is no-go: I don't want to add unnecessary weight to produce an effect.

Weight, in some way, is un-attractive, so it meets your criterias

Louis

[davidalone]

heres an idea:

use masking liquid ( a type of silicon liquid that dries to become a mask) to get that 'random' effect on the frame, then use the methods described on the unmasked portions?

[prendrefeu]

@Tranzformer
Sadly, not exactly. It's a bit hard to find examples of this on the internet because most people (let's just assume nearly all) who do anodizing want a nice, clean finish. Nice pictures end up on the internet. Ugly examples don't.... and I'm seeking ugly in this instance. The closest example I could find that come close is the following, pulled from a recently completed eBay listing for some KCNC brakes that the owner messed up on:



It's awfully close to what I'm looking for. Perhaps with a bit of the original color degraded, maybe if it started off as gold or red, the end result would look stained/rusted and in decay even though it's aluminum. The same could be done for the seatpost and stem (even the crank). A sort of beautiful ugly.

The purpose? When the build actually comes together I'll post a background on it, but a brief description would be "unattractive urban high performance stealth bike."

I figured I would ask around to see if anyone has attempted similar intentionally. Usually when chemicals are used to clean off the anodized layer, the chemicals are washed away along with what was removed. In this case I want to keep the look and not have the harsh chemicals continue to eat into the metal, threatening the strength of the metal. I don't know too much about metals/chemicals and want to learn more.

At the moment I'm debating whether to take this degraded route, or move more towards a subdued 'gunmetal' all around look.

@davidalone

Masking liquid?! I'm intrigued! Do you have more information about this. I'm already thinking I could use that same technique for other purposes too!
Wow!


Thanks for the ideas everyone, it's helpful.

[genesis692]

So you're kind of going for the cycling version of a rat bike? This sounds really interesting!

The only method that I know will work for sure would be to create some kind of harsh environment that will accelerate the degradation. At work we do a lot of testing for things like galvanic corrosion in a salt spray rig....basically just a sealed enclosure at high temperature with a continual mist of salty water. Pretty much anything will corrode eventually.

The benefit of doing it this way would be that you could observe the changes over a longer period of time and remove the parts whenever they've achieved the look you're after.

[bombertodd]

You might try spraying Greased Lightning Cleaner out of a spray bottle. Spray it on, let is sit for a minute or two, then wash it off, and repeat until they look like you want.

http://www.rcnitrotalk.com/de-anodizing ... -aluminum/