Introduction: Anodize Titanium!

Learn how to anodize titanium at home using only a few simple things that you probably have lying around.

I'll walk you through how I anodized my new titanium cyclocross bike.

Step 1: Materials

0. Titanium

1. Rubber gloves (to avoid/prevent electrocution)

2. Plastic bowl/bucket/container

3. Small piece of sponge (1 x 1 x 1 cm), or a small piece of cloth (e.g. small strip of towel)

4. Voltage source that can be adjusted from 20-120 V. I used a commercial lab bench supply, but most people don't have these lying around the home. A good solution is to buy twelve 9 V batteries and connect them together in series. This allows you to adjust your voltage in discrete 9 V increments, or you can add a couple smaller voltage batteries in series as well.

5. Alligator clips to connect to your workpiece

6. Comet cleaner (I used this because it is cheap, i.e. less than a dollar), baking soda, TSP (trisodium phosphate), ammonium-phosphate, or Borax. Basically, anything similar to these products. Coca Cola or Pepsi will also work.

We'll be using some simple chemistry and electricity to perform magic!

Step 2: Get Things Ready

Fill up your plastic container with a few ounces of water.
Pour in about a tablespoon of your cleaning powder.
Stir/shake it up a bit.

Put your rubber gloves on so you don't electrocute yourself.

Step 3: Electricity

Using the color/voltage chart, connect a few batteries together to get the voltage corresponding to the color you want. Choose a slightly lower voltage (5 to 10 V) to test your voltage/color. I found that my method produces colors about 5 - 10 volts less than this chart (i.e. I got a nice blue at 35 V and pink at 85 V). Or adjust your power supply, if you have one.

Important note: once you go up in voltage and add another color (e.g. pink over blue), you can't go back to a color at a lower voltage.

However: The anodized layer (an oxide layer, I think) is pretty thin, too, so if you screw up or don't like it down the road, you can put some elbow grease into it and buff it out. Using scotchbrite, high grit sandpaper, or similar will brush/polish your titanium right up. What an amazing element.

Connect your alligator clips to the positive and negative terminals of your power supply or battery array.

Step 4: Apply the Magic

Connect the positive electrode (alligator clip) to your piece of titanium.

Grab the small piece of sponge with the negative electrode. Try to make sort of a paint brush with it.

You may chose to take a precautionary measure and wrap tape around the alligator clip and sponge such that you won't short out your power supply on the titanium.

Or ditch the sponge and use a piece of cloth.

The object here is to have something that will hold a bit of the water/electrolytic solution that will be "painted" on the titanium.

Step 5: Mask and Paint

I didn't want all of the titanium colored, so I masked it off with electrical tape. I'm sure most other tapes that won't absorb water will work just fine.

You may also choose to clean your titanium to remove fingerprints, dirt, etc.

Find an inconspicuous spot on your piece of titanium to test your color. Start with a lower voltage and increase it until you get the color you desire. REMEMBER: you can not get a color at a lower voltage once you've applied a color with a high voltage (e.g. once you get pink at 85 V, you can't get blue at 35 V)

"Paint" your titanium!

I noticed the colors at the lower voltages seem more stable and consistent. You can see in the pictures that the blue is a nice, consistent, smooth color whereas the pink has a yellow hue to it (yellow comes just before pink when anodizing Ti) and is very splotchy (probably because I didn't clean the frame very well, and because the same voltage wasn't getting to the whole surface evenly).

Step 6: Marvel and Awe and Make Your Friends Jealous

Some feedback from a bike forum I posted this on:

"I love you?

edit: seriously though that's cool as two dogs " - Nick!

"Whoah, that does look real nice though. " - DonPenguino

"That looks amazing man." - Mr. Panda

"That is really cool!" - sage

"I'm gonna cry, that's beautiful. " - Charlie Short


lost+kiwi made it!(author)2016-12-02

Great tutorial, I will be trying this on some of my broken frames. As I have several tig welders do you think there will be anyway to use one as the power suppy?

goldscott made it!(author)2016-12-02

Thanks! I don't think TIG has the correct kind of power supply for this. You want to be able to set a constant voltage, not current.

radr3j made it!(author)2016-02-26

Hey goldscott, I have a question about the power supply. I looked up that model in the picture and it only shows 0-30V. I dont know that much about electricity, but how did you get that to 110V? I want to buy this for some custom knife work.

goldscott made it!(author)2016-02-29

The PS that I posted was just an example. A proper lab supply that goes to 100+ V is pretty expensive. That's why I suggested batteries.

blackparade11 made it!(author)2016-01-12

How can i make titanium green? I've tried many times, it didn't work

Thank you

goldscott made it!(author)2016-01-13

You have to use the right voltage - around 110-120V. Start with a lower voltage and you should see it turn pink, then purple, then green as you ramp up the voltage. See the chart in step 3.

blackparade11 made it!(author)2016-01-26

It did turn green, but some parts of titanium got burnt. Do you have any explanation for this?

Thank you

goldscott made it!(author)2016-01-26

What do you mean by burnt? Can you post a picture?

blackparade11 made it!(author)2016-02-02

It's like this, is it because of titanium grade? or what? Importantly, I used ammonium sulfate into the water to make color

goldscott made it!(author)2016-02-02

Ammonium sulfate is a good electrolyte. Perhaps the titanium needs to be cleaned of any surface oils before you attempt to anodize it.

How exactly are you applying electricity to each piece? I see a wire wrapped around one of the rings. Is that the positive electrode? What are you using for a negative electrode?

YutthanaK made it!(author)2016-02-10

So fat i can anodize green, but i cant make the rainbow color. Do you have any suggestions for it?

Thank you in advance

goldscott made it!(author)2016-02-16

You want to create a rainbow? Each color is a different voltage - see the chart in step 3.

PaulD117 made it!(author)2015-12-30

The colors obtained by this method are "interference" colors that arise because the top surface of the somewhat transparent titanium oxide has a reflectivity (for light) that is comparable to the reflectivity of the titanium metal that is under the oxide. The colors have some similarity to the "temper colors" that you can be seen on plain carbon steel when it is heated. To get this effect requires two things :

1. the oxide thickness is roughly the same length as the wave length of visible light

2. oxide and metal have similar reflectivity for visible light.

It won't work for aluminum because aluminum oxide isn't reflective enough.

The wavelength of light varies with it's color.

For more, google "carbon steel temper colours"

pdubya, BSc, MSc, PhD (all in metallurgy)

goldscott made it!(author)2015-12-30

Thanks for the explanation, Paul!

bowmaster made it!(author)2010-06-30

Sweet, I'm going to make my titanium spork blue!!

MercuryCrest made it!(author)2014-08-24

Did it work? Anything you'd recommend?

I spoke to some metalsmiths at my local makerspace and they told me I could get the bluing effect on titanium with a propane torch, so I think I'm going to go with that method.

MercuryCrest made it!(author)2014-08-24

EDIT: that is to say, I'm going to do this on my own titanium spork.

makerbuilderbaker made it!(author)2014-06-16

I recommend looking around Amazon or Lab surplus stores for old electrophoresis machines. They are lab grade adjustable power supplies, that are available for cheap. Check out Hoefer brand.

MachineHead1011 made it!(author)2014-01-23

where can i buy the power supply? i see a lot of power supplies but most only goes upto 15v and the highest i've found only goes upto 90v. help please. thank you

goldscott made it!(author)2014-01-24

Finding a nice adjustable DC power supply for these high voltages will be expensive. Check out Agilent, Tektronix, etc.

I'd suggest finding a local hackerspace, college lab, etc.

Sins+of+Avarice made it!(author)2013-10-06

2 questions.

what voltage would I need to get a redish red?

also what type of balisong is that in the picture?

goldscott made it!(author)2013-10-07

Look at the chart in step 3. Maybe 90-110V. You'll have to experiment.

I'm not sure about the knife. That is a picture I found online (to show the battery chaining).

xXcAsPaXx made it!(author)2013-09-04

You do realize 9v batteries are designed to clip into each other?

nycresistor made it!(author)2013-02-09

mastermakoko, you can use anything with phosphoric acid, which is most soda/cola. MiracleGro is primarily ammonium phosphate and works well too. There are several coffee maker descalers that make great electrolytes, TSP (trisodium phosphate), Cafiza, and a few others that have the phosphorus compound.

nycresistor made it!(author)2013-02-09

Shazni, you need DC voltage because you need an anode (anodising) and a cathode. You also need a way to protect yourself from high amperage. The circuit will draw several amps at the higher voltages. This can be very hazardous and will fuse the coil on your VariAC or dimmer. There are many commercial DC bench power supplies available that have current limiters built in to keep you safer. It's still a dangerous project even with a good DC supply. Rubber gloves, rubber shoes, no distractions. Put your cell phone on mute.

shazni made it!(author)2012-03-12

in my country we use what do i do
do i use ac power with a dimmer switch only or do i need a transformer to get DC power...then what would the Amperage be required? will 1.5 amp or 1 amp be enough? also maximum voltage?
for my Styrofoam cutter i used a 12v 1 amp transformer with a dimmer switch 12 v being the maximum.
please pretty please help as i have fallen in love with this new craft....i would like to try it's cheaper....but i see it's not possible as you have to use chemicals which would probably not exist here and also be very expensive....i now have to check hardware stores and ask if they sell titanium sheets :-) (hopefully they would know what I'm talking about!)
i'm looking forward to your reply.

goldscott made it!(author)2012-03-12

You need DC power. 1 Amp is enough.

You need 30-90 VDC or so.

Titanium is expensive and difficult to find.

Elcolombiano made it!(author)2012-02-06

Hi. Could you tell me if the voltage is the same to anodize aluminium?

I am going to make 200 leaf of aluminion for a proyect but i dont know how to obtein the same color for all of them.. the idea are 200 yellow, 100 read, 100 bue etc..

What to you sugest for that? thanks..

Steven from Colombia

goldscott made it!(author)2012-02-06

You cannot anodize aluminum with this method.

Elcolombiano made it!(author)2012-02-06

Thanks.. :(

squiggy2 made it!(author)2011-06-17

that's really cool!
Would this work with aluminium as well, or is that a different process.
Also, is the point of the cleaner/borax/pepsi just an electrolyte, ie would salt water work, or are there chemical reactions going on?
Edit: Sorry, I just read the comments about aluminium. question about the electrolyte still stands though

goldscott made it!(author)2011-06-17

This process will not work with aluminum.

The cleaner/borax/pepsi is just an electrolyte. Salt water should work as well.

mastermakoko made it!(author)2010-07-05

so basically i can just use coca cola or pepsi as the anodizing compund?

goldscott made it!(author)2010-07-06


aero007 made it!(author)2009-07-02

dont you have pics of that ?. btw funny i have a brush like that in the picture. about the alu anodizing, i believe using an acid instead of water would work? have you tried using dyes in the electrolyte solution rather than using those voltages ? it seems a high voltage to use ?

goldscott made it!(author)2009-07-13

I'm sorry I didn't take pictures of it. I know that aluminum anodizing requires dyes, but titanium anodizing does not. You need these high voltages to anodize titanium. I'm not too knowledgeable about the aluminum anodizing process, but it's dye based instead of voltage dependent.

aero007 made it!(author)2009-07-02

could you expand step 4 ? what is the point with the paint brush ?

goldscott made it!(author)2009-07-02

Basically you have a small piece of sponge (soaked in the electrolytic water solution) in the alligator clip (negative electrode), and you use it as a sort of "brush" to "paint" the solution onto the titanium. The titanium will change color when there is electricity passing through the solution.

arirang777 made it!(author)2009-05-27

Can we transfer this procedure to Aluminum instead of titanium? Great Instructable by the way

goldscott made it!(author)2009-05-28

I doubt this method will work on Aluminum, otherwise more people would be doing it. Here's a good page to get you started on your own:

westfw made it!(author)2009-05-26

Huh. Last time I attended an anodizing tutorial they were complaining about how hard it was to prep titanium; all sorts of nasty cleansers were involved - but it sounds like you got away with very little cleaning? Neat!

BTW, I think I like your "mottled" pink BETTER than a solid, even color on that size of piece.

Niobium (aka "columbium") can also be anodized like this. Anodized Aluminum colors are produced with dyes rather than optically-active oxide layers, so even if you CAN anodize aluminum with a similar setup, you won't get colors.

A very good reference/supplier is Reactive Metal Studios, although they specialize in jewelry-sized things. Download their catalog; it's good reading!

CameronSS made it!(author)2009-05-19

According to Theodore Gray, Diet Pepsi, or any other cola, also works. You just need something with phosphoric acid.

goldscott made it!(author)2009-05-20

Oh yes, forgot about cola. I'll update the instructible. Thanks!

Nerdz made it!(author)2009-05-19

Will this technique work with any metal other than Ti? It would be cool to be able to do the same to Aluminum.

goldscott made it!(author)2009-05-20

It won't work with aluminum, but it may work with other elements in the same column on the periodic table as Ti. But I really don't know; I know very little chemistry. Doesn't hurt to experiment, though.

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