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Sunday, February 26, 2012

Anodizing and dyeing Aluminum and Titanium, at Home

Anodizing and dying aluminum without battery acid - Observations

Video and writeup below
The anodizing and dying of aluminum parts at home has long been a popular project for many people. But the use of battery acid, typically (29% to 32% sulfuric acid) causes concern and reluctance, and prohibits others from even trying to anodize aluminum at home. It can be difficult to store, dangerous to skin and clothing, and in general, not fun to work with. OSHA lists it as corrosive. This project provides an alternative to the use of liquid sulfuric acid and uses instead, a granular pool chemical that is easy to find, mix, store, and work with. OSHA lists this chemical as only an irritant with no shipping restrictions. Disposal is straightforward using baking soda to neutralize and the results are comparable to those obtained with the use of the sulfuric acid method. The alternative chemical is sodium bisulfate (NaHSO4) the sodium salt of sulfuric acid but in weaker form.  It is also known as sodium hydrogen sulfate and is used to lower the ph in home swimming pools. As in the use of any chemicals, care and caution are in order. The following video is a project overview followed by a step- by- step write-up:

Read More and See Video...

Anodize Titanium with household items

Positive terminal to titanium object, Negative to sponge. I used Coke Zero for dipping the sponge.

You can use something as simple as CocaCola (sugar free = less sticky) to dip. Comet cleaner mix also supposedly works. The voltage you supply determines the color of your anodized titanium. In my case, my power supply only went up to ~40 volts, which ends up being around the blue spectrum. The higher you go, the further you travel through the rainbow. There is some wavelength cancellation, so the colors don't correspond perfectly. It goes: Bronze, Blue, Light blue, Yellowish, Purple-ish, Cyan, Green. This is a range of 20v-100v supplied. If you do not have a variable voltage power supply, you can daisy chain 9v batteries by snapping them together. They only snap together in series, which adds 9v each time. Note: You can always ADD voltage to change color, but you can't go back to a "lower voltage color" once you have changed it.

Second method: Dip your objects in Coke, + to Titanium, - to coke. Use sugar free! Less sticky.

It will bubble as it works.


I use to work in an Air Craft Manufacturing Plant. And they had a large Anodizing Area, in the Warehouse. With Big Acid Vats, Chem Etching, Anodizing Vats and I don't even know what else. I was a "Hand Finisher" and would go down there, some times to grind cracks out of Aluminum and Titanium Parts. So that they could be welded and then ground and polished by me, before Anodizing. Otherwise, they would have to be scrapped. Because, the High Speed Vibration that happens when a Fighter Jet is Flying. Would cause the Cracked Parts to completely fracture, at some point. I thought the Anodizing was very interesting. But, I never thought of trying it at Home. It seemed very complicated and the fumes from all of those Chemicals. Gave me a Soar Throat, every time I worked down there for just a few days. So, I think that it is great that, there are less Toxic ways to "Do this at Home"...


Anodizing and dyeing Aluminum and Titanium
Anodize titanium at home - Hack a Day
Anodize Titanium with houshold items - Imgur
Anodizing and dyeing aluminum without battery acid - Hack a Day
Anodizing and dying aluminum without battery acid - Observations
Electrochemistry Encyclopedia -- Anodizing

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