Ghetto aluminum anodizing

Projects other than metal casting.
davidbraley
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Joined: Sun May 29, 2011 6:13 pm
Location: Fort Collins, Colorado

Re: Ghetto aluminum anodizing

Post by davidbraley »

Thanks Guys,

But, this is the part where I discourage everyone. The first thing I want to say about anodizing at home is.... it's not easy to get good results. You really need to work for it. :cry:

The HowTo of anodizing is easy to find online. The link above is one of the very first links I used to teach myself how to do it.

If you are really serious about this, you need to register over on the forum at the Caswell site. They have an anodizing section on their forum that is absolutely the place to get answers to any problems you're having. Don't buy the Caswell plating guide. It's crap. But, the plating guide at the link above is very good.

I studied anodizing for about a year before I actually built my setup. I studied the enormous number of different problems people have with their efforts, and every one of them boiled down to one thing; You must be very very clean to do this. Your water must be as pure as possible. Distilled pure. You can't drag chemicals from one tank step to the next, so you rinse, and rinse and rinse, and then rinse again between steps. What do you rinse with? You guessed it, distilled water. Your parts must be surgically clean before you start, and before they hit the next tank. You NEVER touch the parts. Something as simple as a finger print will ruin your finish. Your temperatures in each bath must be exact, and the PH levels perfect. So you need to have a way to control things.

It's a five tank system. After cleaning the parts, and I mean perfectly clean, they go into a special cleaning tank that strips off the oxidation layer on the surface. This oxide layer forms in about a second when bare aluminum is sitting in plain air. So after the special oxidation strip, you move the part to a rinse step in such a way that NEVER lets the part dry. This, as mentioned before is because it only takes about a second to re-form an oxide layer on the surface of the aluminum. Once it's been rinsed very well, the constantly wet part is then moved to the de-smutt tank. This tank strips off the alloys in the aluminum on the surface just a few molecules deep, leaving a layer of a few molecules deep of pure aluminum on the surface. Then you rinse again, never letting the part dry to keep the air off of it. Once clean, the wet part moves to the anodizing tank. Anodizing typically takes about an hour. The part is kept wet as it's moved from the anodizing tank to be rinsed again. Once clean, it's moved wet to the dye tank (the color tank). After the dye tank it's moved wet to be rinsed again, and then moved wet to the sealer tank. After the seal tank, the parts are safe again in plain air.

As you can see from my short description, if you want your parts to come out good, you really need to be organized and prepared. You will find that most guys that do this at home get pretty crappy results. No, let me rephrase that, most home anodized parts look like shit! I am not about that, so I spent a lot of time and money with my setup to get the same level of quality the big commercial shops do. I do not recommend this type of thing to anyone who is not super detailed oriented and super clean.

I know, I'll end up being the big downer on this forum.

Take care,

David
-David

I cut it off three times! And it's still too short!
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GypsyTinker
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Joined: Mon Jun 06, 2011 12:56 pm

Re: Ghetto aluminum anodizing

Post by GypsyTinker »

Not a downer in my book! Great synopsis of the way to do it right, by someone who has shown that they can do it right.

That is the only qualification I need to take someone's advice :) Thanks tons! you helped me!
Only the highest standards of precision!
Lambda_drive
Posts: 10
Joined: Tue Jun 07, 2011 7:59 am

Re: Ghetto aluminum anodizing

Post by Lambda_drive »

I appreciate all you guys trying to steer me in the right direction, but it seems like guys are totally ignoring my original post. I understand that to get a good looking anodized surface requires meticulous attention to detail. It's not easy to anodize aluminum and make it look good, and for it to also last a long time. I'm not trying to replicate a professional anodized finish with household products. I just want to see if it's possible to etch aluminum and grow an oxide layer with household products. You guys are probably wondering, why would anyone want to use inferior products when they can use the right thing? Well I have a good reason. I didn't want to say too much about it at first, but I think it'll help you guys understand why I'm trying to do, what I'm trying to do. A little while ago this really big popular energy drink company contacted a bunch of hackerspaces to be in this creation contest. My hackerspace responded and we made an entry into the contest and we were chosen as finalists. So in July they're going to fly our 4 person team to new york for a 72 hour build off competition. So being a build off competition Were most likely going to be using metal somewhere and that gave me an idea. Since their energy drink is so acidic, about a 2.5 pH, you might be able to use it as the acid for anodizing aluminum. I figure if you can use their own product for anodizing aluminum they'll think that's it's really cool, and we'll get some "cool factor" points from that. I want to try it out now to see if it actually works, that way I don't waste my time doing it during the contest. Also the anodized finish doesn't even have to be perfectly uniform, or thick. As long as it can hold a color that's all we need.
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Nudge
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Joined: Sun Jun 05, 2011 6:18 pm
Location: Auckland, New Zealand

Re: Ghetto aluminum anodizing

Post by Nudge »

It sounds like it would be near impossible it anodize an "as cast" part due to not being able to clean it to a good level.
I think I will stick to paint :D
That is a good write up.
Thanks David

It would Still be good to see pics of your setup :P
I like to build "Stuff" using Stuff that costs Stuff All!
Lambda_drive
Posts: 10
Joined: Tue Jun 07, 2011 7:59 am

Re: Ghetto aluminum anodizing

Post by Lambda_drive »

There isn't going to be any casting involved in the contest. They're supplying us with all the tools and materials we need. They haven't given us the build theme yet, but they're supposed to give us some hints before the contest begins in July.
davidbraley
Posts: 29
Joined: Sun May 29, 2011 6:13 pm
Location: Fort Collins, Colorado

Re: Ghetto aluminum anodizing

Post by davidbraley »

HA! OK, now I'm really going to be a jerk! Harry, you can ban me if you want. 8-)

LambdaDrive, If I learned that you could anodize aluminum with an energy drink, I would immediately become a whistle blower and contact the FDA to put the company under investigation. Maybe even closed down. I'm sure I'm not the only one who thinks this....
-David

I cut it off three times! And it's still too short!
Lambda_drive
Posts: 10
Joined: Tue Jun 07, 2011 7:59 am

Re: Ghetto aluminum anodizing

Post by Lambda_drive »

I don't think it's quite that bad. People actually use Lye in a lot of foods you've probably had before, Lye in food preparation It's used t chemically peel fruits and vegetables, thicken ice cream, soften olives, make pretzels crispy, it's used to make Hominy and Lutfisk, and in Chinese noodles. People even use Lye as a hair relaxer.

The energy drink is really acidic, but it's not that bad. Lemon juice squeezed straight from the lemon has a pH of 2.4, and it can clean a penny and make it look brand new. Sodas like coke and pepsi also have phosphoric acid and they can clean pennys too. Also stomach acid has a pH of 1 to 2 and is composed of hydrochloric acid (HCl). Energy drinks are quite acidic, but you have stronger acids already in your stomach. So the occasional energy drink or soda now and then is fine, but if you have a energy drink habit you'll erode your tooth enamel pretty fast.
http://vermontdentistry.com/blog/2011/0 ... w-mouth-2/
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Harry
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Re: Ghetto aluminum anodizing

Post by Harry »

Straight talk wont get anyone banned around here. Thanks for the information David, your results are excellent and show the effort you have put into it.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun...
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