My Tutorial on Anodizing Titanium

Tom Anderson

Artistry in Titanium
Here's the new tutorial on Anodizing Titanium:

The process of anodizing titanium involves immersing the object to be colored in a container with a titanium cathode inserted and filled with an electrolyte. Passing a DC charge through the electrolyte solution will cause a microscopic oxide film to adhere to the part. The thickness of the oxide film determines the color.

Attached is a color chart that lists the various colors obtainable through the various effective DC voltage ranges:


Note that these colors can also be obtained by heating the part to create the oxidation, but that process is not as accurately controlled.

The equipment used consists of the following:

1. A DC power supply that has a range of 0 to 125 volts. The wattage (amperage x voltage) of the power supply will determine the size of the part that can be anodized as well as the speed of anodization. For most knife handles (approximately 6” long or smaller), I would recommend using a 1-kilowatt DC power supply (approximately 7 amps x 150 volts).

2. A non-conductive container, large enough for the cathode (see #3) and the part to be anodized.

3. A strip of titanium to be used as a cathode. The surface area of this strip must be greater than the surface area of the part being anodized. For safety, the cathode can be covered with nylon webbing to avoid accidental contact with the part during immersion.

4. Electrolyte solution. This can be a simple solution of 5% trisodium phosphate in distilled water – enough to fill within 1” of the top of the container.

5. Leads for the + and – terminals between the DC power supply, cathode (titanium strip), and anode (see below).

6. Anode: This is a small hook made from titanium wire to which the part is attached for immersion.

7. Thick rubber gloves to be worn as a safety measure during the anodizing process.

8. A bottle of cleaner (Windex ammonia-based window cleaner works well).

9. A small paintbrush with a metal ferrule. This is used for reverse-polarity brush anodizing described later.

Equipment setup and use:

NOTE: Exercise caution when working with the power supply turned on to avoid electrocution. Always wear rubber gloves when the power supply is turned on. Do not attempt this process while working on an electrically conductive surface!

Fill the container with the 5% TSP/distilled water solution (electrolyte). Attach the cathode (-) lead from the DC power supply to the cathode – making sure the connection is well above the electrolyte level.

Attach the anode (+) lead to the titanium hook. Exercise caution not to bring the two leads together.

Turn on the power supply and adjust the voltage to achieve the color (as shown on the attached chart). Turn the power supply off.

Clean the part to be anodized with the ammonia based cleaner. Attach the part to the titanium hook/anode, and submerse it in the electrolyte bath.

Turn the DC power supply on until the color appears on the part. Turn the DC power supply off when the color is achieved and before removing the part from the electrolyte bath.
Re-clean and dry the part to remove any traces of electrolyte.

Multi-Stage Anodizing:

Applying different colors to a titanium part can be achieved using the equipment listed previously with several different techniques. Besides ensuring safety, the most important thing to remember is that the oxide film (color) applied during a higher voltage session will remain when applying an oxide film (color) at a lower voltage setting. For instance, you can submerge a titanium part that had been partially masked when a 40 DCV color (powder blue) was applied and apply a 25 DCV color (purple) without affecting the powder blue color.

I have attached several photos illustrating the results of various multi-stage anodized titanium parts.


This knife has had multi-stage anodized scales that were accomplished with the following (basic) steps:

1. Anodize the engraved bolster area with gold at 15VDC. Sand off the top to make it look like gold-filled engraving.

2. Mask off the engraved bolster area, apply a light coat of spray glue to the “overlay” area.

3. Anodize the light blue color at 43VDC.

4. Remove the spray glue and reapply another light coat.

5. Anodize the dark blue color at 28VDC

6. Remove the spray glue.

7. Anodize the purple color at 19VDC.

NOTE: All parts were anodized using the immersion method described previously. The stepped pivot screw collar is a separate piece, anodized at 28VDC.


This is another example of multi-stage anodizing. Here the overlays were anodized at 65VDC to achieve the green-gold color in the file work. Then, the tops of the overlays were sanded, cleaned, and re-anodized at 28VDC to achieve the blue color.
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Reverse-polarity anodization:

This is another technique using the same power supply and electrolyte, but using a paintbrush with a metal ferrule to “paint” the color on the part. The negative lead (cathode) is attached to the ferrule on the paintbrush and the positive lead (anode) is attached to the work piece. Again, rubber gloves must be used to avoid electric shock.


In the above photo, I’m anodizing the slots in a pocket clip using a small paintbrush. I created a “rainbow” effect by gradually slowing down each brush stroke. The following photo shows the results.


I carefully sanded the top surface of the pocket clip to remove any overruns, and cleaned it again using ammonia-based window cleaner. The next step involved reconnecting the power supply leads to the cathode strip (-) and the titanium wire hook (+), setting the voltage at 28VDC, and submerging the pocket clip in the electrolyte bath. The following photo shows the results.


Because the slots were anodized at a DC voltage setting greater than 28, the colors remained after anodizing the rest of the part at 28VDC.

The following photo shows the standard bath setup used to apply the blue color on this pocket clip.


The following is a good reference link to the process of anodizing titanium and other reactive metals:

General notes:

Anodizing titanium is a different process from anodizing aluminum. There are no dyes or acids used and, thus, the range of colors is limited. (For example: bright red or black cannot be achieved when anodizing titanium with the process described herein.)

Other differences between the processes used in anodizing titanium and aluminum include:

1. The surface of the titanium part is not hardened (like with TYPE 3 anodization of aluminum), and can be easily scratched.

2. A microscopically thin oxide layer that is refractive creates the color.

3. The color will dull from skin oils (or other dirt) during handling. Removing the skin oils with an ammonia-based cleaner, acetone, alcohol, etc can restore the color.
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Thanks for the tutorial Tom. It came at a good time for me. I am nearing completion of a folder and was thinking about anodizing the liners. I am leaning toward doing that now, using your tutorial.
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Anodizing Ti, Power supply question

Tom and the rest of the DAWGS that know,
I did a little shopping around last night, and found that most (what I found, not everything that's available) of the power supplies cost upwards of 200+ or -, is there a "hobby" type Rectifier that doesn't cost an arm and a leg? That fits the requirments you mentioned? I found a couple that were very affordable, but the description didn't have the voltage like you described it, I am not comfortable with electricity (yet), and I have a little understanding of how some of this stuff works, but the way the less expensive power supplies seemed to have lower voltage, or it was written differently, the better ones said the range was 0 to 120 volts, the cheaper one said ( I can't remember exactley) 50VDC or something like that. I follow directions very well, actually to a fault sometimes, only because I don't know or understand everything I should probably know. It's safer that way, until I can get to the DAWGS that do know and understand! It would be great if you could direct me to a moderately priced Rectifier/Power Supply, one that I know is safe and will give me the results that I want. I do have an electrician that I can contact, I'm not sure if he knows about these type of things, on the other hand I will be waiting a while for him to have time for me, he won't charge family, (I have to make him take payment for everything he does) he's a great bro-n-law, that works 16 hours a day, weekends too. So I would rather buy a unit that I could safely use AND get the results that I'm looking for, if there is a particular unit you can direct me to, it would be greatly appreciated,
BTW, if there are any other Dawgs out there that may have any suggestions, I'll gladly accept any guidance y'all can provide.
I just bought a 0 to 125 volt DC supply from the folks a MPJA ( it looks like it's the same supply sold by the Reactive Metal folks but was $97 instead of $227. I just received it so I haven't had a chance to do any anodizing with it but I did hook it up to a meter to see if it's display was accurate and it went from 0 to 125 volts staying pretty much right on with the meter.
Is there somewhere to buy a complete anodizer kit. I have no comfort level at all with electrical and would prefer to spend money rather than time to figure this out.
I just bought a 0 to 125 volt DC supply from the folks a MPJA ( it looks like it's the same supply sold by the Reactive Metal folks but was $97 instead of $227. I just received it so I haven't had a chance to do any anodizing with it but I did hook it up to a meter to see if it's display was accurate and it went from 0 to 125 volts staying pretty much right on with the meter.

By chance do you know what the item number is? I checked the site and they have some great stuff and better prices! Thanks! Rex
Would this work for the DC power supply or is it too light?
Single 0 to 50 VDC 3A power supply
• Adjustable current and voltage output
• Over current and short circuit protection
• Dual 3 1/2 digit LED displays

The Elenco XP-752A Variable Voltage Power Supply features fail-safe automatic overload protection with coarse and fine control of voltage and current output. Ideal for labs, shops, schools home and industry. The XP-752A contains 1 fully regulated 0 to 50VDC 3A power supply.

• Supplier code : XP-752A

Thanks for the help.
I really do not understand electronics so please be gentle. Is 1 amp at 100 volts the same as 2 amp at 50 volts in terms of anodizing?