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Anodizing Titanium Rings

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I love the colors of anodized titanium, and I really enjoy making chainmail out of titanium rings I've anodized myself.

Anodizing is a process which uses electricity to produce a coating on the surface of a metal. Titanium is interesting because the process naturally produces different colours without adding extra dyes or pigments.

This instructable will show you how to color small pieces of titanium using readily available materials such as 9V batteries and Coke or baking soda. (It does not cover "painting" designs on large pieces of titanium.)

The results are not very predictable, but part of the fun is trying different things and seeing the results.


 
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Step 1: Things you will need

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Plain titanium rings. I got mine from http://www.theringlord.com/. Get quantities and sizes appropriate for the project you have in mind. I use larger rings as hooks to hang the small ones on during the anodizing process. You will need either some large titanium rings or a piece of titanium wire bent into a hook shape.

9V batteries. Three is about the minimum number to get nice colours. After taking the pictures for this instructable with three batteries, I tried using nine batteries. This produces a larger range of colours (and a more dramatic chemical reaction), and I highly recommend it. (It's also more dangerous, so be careful.)

Battery snaps. (See picture.) You'll need these (or some kind of battery holder) to connect the batteries together. You can get them at a store like RadioShack or anywhere that sells components for electronics projects.

An electrolyte solution. Lots of anodizing instructions mention Coke and Pepsi, and these do work. However, different soda formulas work differently (Coke Zero doesn't work at all). I've also had good results with grapefruit juice. For this instructable, I tried two different things: white vinegar and baking soda dissolved in water. Both worked, but the same number of batteries produced completely different colours. You may want to experiment with a few different things and see what works best for you. (Anything acidic is worth a try.) Keep in mind, though, that it will be easier to see what's happening if you use baking soda than if you use cola (because the cola is dark). 

An empty margarine tub or similar container to hold your liquid.

Some scrap metal. This doesn't have to be titanium, but it needs to have an equal surface area to the rings you are anodizing. I used a large coil of thin steel wire, which worked for me.

Wire strippers  and a small pair of pliers will make it easier to connect the wires. Also, if you have a multimeter you'll be able to check your circuit to make sure your connections are good.

Some tape to hold connections in place may help. You could also use test leads with alligator clips to connect the positive and negative ends of the circuit to the titanium and the scrap metal. (I didn't happen to have any, but it would be easier.)

You should really wear rubber gloves - I didn't, but I also shocked myself. Twice.

shazni2 years ago
wow....i'm falling in love with a new craft...please may i know if i can use direct ac power connected to a transformer and a dimmer switch....that way i can control the power and not waste battery....
also...what is titanium? can i use aluminum sheets? will they change color? i want to do a metal wall decor with shades of color...i checked out the site you gave and my mind just went crazy...only i have to figure out how to do it...do you know? would you put up an instructable? :-)
Thursday (author)  shazni2 years ago
You can use a variable voltage supply. I don't know about ac power.

Titanium is a different metal from aluminum. Aluminum can be anodized, but you have to add dyes to get different colors. I don't really know how to anodize aluminum - I think you might need special chemicals as well.

You can buy titanium in sheets (but it gets expensive). I have "painted" on a sheet of titanium, but I'm not sure if I remember all the details. If I try it again I'll do an instructable :)
shazni Thursday2 years ago
thanks...looking forward to your future instructables :-)
big-jamie2 years ago
What wire gauge are you using in this project ? and how do you cut your wire, you have very neat and tidy joints ?
Thursday (author)  big-jamie2 years ago
It's 18 AWG, but I don't cut it myself - I buy pre-cut rings from www.theringlord.com.
mooseo3 years ago
I'm puzzled by using baking soda. I thought you said that "anything acidic is worth a try," which, I'm pretty sure, doesn't include baking soda.
msw100 mooseo2 years ago
how is baking soda not acidic ?
iBurn msw1002 years ago
Because it's BASIC. The exact opposite of acidic.
Thursday (author)  mooseo3 years ago
Sorry, I guess I should have been more clear. What you actually need is an electrolyte. According to Wikipedia, "Electrolytes commonly exist as solutions of acids, bases or salts". Baking soda's not an acid, but it is an electrolyte. On the other hand, Coke and Pepsi work because they contain citric acid.
Thursday (author)  Thursday3 years ago
Forgot to include the link: http://en.wikipedia.org/wiki/Electrolyte
_Scratch_2 years ago
Oooh, titanium chainmail!
Bitszu3 years ago
I work for a company that does this on a large scale.
The colour that you get is dependant on the voltage in the system( and the gage of the wire to some extent). If you can vary that you can have greater controll over the end result. The same trick can be done with niobium rings as well, the colours are far more vibrant. Choosing the right Titanium can help as well- the comercialy pure stuff wont colour at all, you need a Ti alloy.
Looking to set up a bigger system or want some tips or tricks? check out the forrum at theRingLord.com
rimar20003 years ago
Very interesting!

I have two questions:
1) only titanium? Why not ie iron, aluminum, copper, zinc, stainless steel?
2) Can I use the car battery charger? It gives 6 or 12 volts for charge, this is around 9 and 14 volts.
Thursday (author)  rimar20003 years ago
1. As far as I know, titanium is the only metal that produces colors like this.

Aluminum can be anodized, but it's a different process and I think you have to add some kind of dye. I'm afraid I don't understand the chemistry well enough to explain why - sorry!

2. You can use any voltage source you want, but I'd be surprised if you got any colors other than bronze with that low a voltage.

Arx Thursday3 years ago
Niobium works the same way, and generally gives a more intense colour. (it's shinier too.)

The reason this only works on certain metals is because their oxides need to be quite transparent, and have a high index of refraction in order to produce the interference that makes the colour.

as far as using a car charger goes, you'll get some colour, but it will depend on the alloy of Ti. You might not get more than a straw colour, or you might even get as far as a bronze or purple.

Those lowest colours on the scale can be very nice, but they're also the most sensitive to oils on their surface.

I anodized a titanium handlebar for my bicycle to a purplish blue (around 17v IIRC), and it changes colour when it gets wet. Fingerprints change colour too. (It changes back if I clean it and let it dry)

If you really want to do a bunch of anodizing, check out the "how-to" pages on mrtitanium.com You can build a half decent setup for around $50, which will get you a bit more consistent results than a stack of batteries.

Depending how much you play with electronics, you might even have most of it on hand already.

of course, the stack of batteries is safer if you're not comfortable working with line powered equipment.
rimar2000 Arx3 years ago
1) Thanks for the info, it seems very useful;
2) My interest in the subject is just curious or for a casual work, not that I will devote to anodizing.
3) I could not find the link colour.as;
Arx rimar20003 years ago
I'm not sure what #3 refers to.

Pretty much what it amounts to is that you need an adjustable voltage supply. (0-110V will give the full range of colours)
A car battery charger is too low to have much effect. You really don't need that much current either if you're doing small stuff.

If you just want to fool around, you can also flame anodize Ti. It's a little less predictable, but can give a neat finish. Just heat it up with a torch (even a $10 butane torch) You should be able to get bronze, purple, and blue that way. You can also colour stainless steel this way, though it will likely change it's hardness.
Kaiven3 years ago
That is really cool! Are titanium rings cheap?
Jayefuu Kaiven3 years ago
About $65 per thousand.
Kaiven Jayefuu3 years ago
Hmm... doesn't sound so bad. Might be if I plan on making a shirt haha
Arx Kaiven3 years ago
I've made some nice chains and stuff out of titanium and niobium. I think the niobium works out to about $7-10 in material depending on ring size, and titanium is cheaper, maybe about $3.

Of course it depends on size. really big rings will get the job done a lot cheaper.

I'd guess a shirt is probably several hundred dollars of Ti. More importantly, it's a lot of time. I wouldn't recommend it as a first project. A lot of people try it, and give up after they do a 20cm patch.

OTOH, if you're going to take the time to make one, titanium looks cool, and you don't have to worry about rust.
Thursday (author)  Kaiven3 years ago
Titanium is more expensive than other metals, but if you only need a small quantity it's not too bad. If you look at the website I listed (www.theringlord.com) prices for titanium rings start around $8 an ounce, and you'll get 500+ rings per ounce. It does depend what size rings you want, though.

One thing I do is use steel rings together with colored titanium - you get a nice color contrast and the steel rings are cheaper.
stella1113 years ago
Niobium can also be anodized into a pretty broad array of colors.

Aluminium, titanium, and niobium are the only reactive metals.

Titanium and niobium jump rings, split rings, sheeting, coils, and rods in big and small sizes and big and small quantities can be found at some jewelry-making supply sites and at any site that specializes in reactive metals, such as, duh, reactivemetals.com. Jewelry sites often carry already-colored ti and ni components (like jump rings).

Reactivemetals.com also sells variable anodizing devices for appx. $235 and a commercial device for appx. $2350. I don't know anywhere else to buy an non-commerical anodizer. Lucky you if you know how to build one yourself cheaply; if you do, build one for me.
anode5053 years ago
Car battery charger/boosters work well too
Clayton H.3 years ago
Will this work for aluminum or steel rings?
There are some websites with instructions for aluminum anodization at home. This sounds a bit hazardous, as sulfuric acid is involved. But it does seem possible.
Aluminum and Titanium are the most commonly and just about the only materials that are "anodized" -- both work by building up an oxide layer on the material. However, in aluminum anodization you embed a dye (i.e. pigment) in the oxide layer and seal it in while in titanium anodization the color is actually created by reflection/refraction and wave interference through the oxide layer--the significance of this is that there are a limited number of colors you can anodize titanium; white and black are not included and several other colors are impossible/impractical to attain (e.g. Red).

The color of the titanium is determined by the thickness of the oxide layer which is related to the voltage and perhaps the electrolyte used (nitric acid is most common in production applications), while the color in aluminum anodization is most heavily influenced by the dye used (the thickness only matters with respect to how much pigment it can trap).

The best resources for either type of anodization is likely medical devices (see www.danco.net for example) but the paintball community also has a large experience with aluminum in particular.

Steel cannot be anodized--you could try but it would simply rust (i.e. oxidize). There are a few select other materials that can be anodized, but their incidence is either more rare or in a completely different application.
Thursday (author)  Clayton H.3 years ago
No, sorry.

You can anodize aluminum, but it's a different process and I don't know how to do it. There's probably instructions somewhere on the web, though.
instead of connecting all those batteries to the black battery holders you could just plug them into each other directly in a series.
good idea.

That won't accomplish much besides destroying the batteries!
Uhhhh, I believe he means to offset them positive to negative, not a straight on face to face.
What thematthatter means is: plug them into each other in a zig-zag pattern. You plug minus of the first battery into plus of the second, minus of the second into plus of the third. The remaining poles (plus on first, minus on third) will give you 27V
God is in the details.
I think he means leave a + and - for the electrodes.
MonkeyMomma3 years ago
My wedding bands are blue titanium (I <3 them) ...you have to be careful as the color can scrape off after some abuse.

I have to ask -- how did you get the purple vs the blue?
Words from the wise..finish reading before you ask questions
schnitzle3 years ago
What a cool instructable! When I first clicked on it I thought "Oh this will be complicated, but I'll take a look anyway" but it's actually relatively easy and would make a fun science project for kids even! Thanks :D I'm going to have to try this!!
Doesn't look like anyone mentioned that those bubbles are Hydrogen gas being released so don't have an open flame near this procedure.
josefski3 years ago
FWIW, you can build a plug in power supply that would replace the 9v batteries with the transformer from an old amplifier and a voltage doubler (or even quadrupler) circuit. You could even make it variable without too much trouble. Then you would be able to "dial" in your results with the turn of a knob.
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