How to EASILY Anodize Titanium at Home (2 Methods)

Titanium anodizing is an extremely cool and rewarding project that is very easy to do at home. Anodizing is used industrially for enhanced corrosion resistance on metals like aluminum. Anodizing is also used as a decorative process for titanium jewelry as a wide range of colors can be achieved.

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Step 1: Learning the Science Behind Anodizing

Please note that the science behind anodizing can be complicated and hard to understand. Please skip to the next step if you want to jump right into anodizing. I would be more then happy to answer any questions through a PM or the comments below.

There is great website I found that explains how anodizing works better than me. The link is http://mrtitanium.com/interference.html

Step 2: Method 1 - Using a Chemical Cell - Intro

The first method of titanium anodization is done using a chemical cell. The titanium piece is is made the positive anode (hence the name anodization) and submerged into an electrolyte bath (borax and sulfuric acid are commonly used).

Step 3: Method 1 - Using a Chemical Cell - Step 1

Gather Parts and Tools

You Will Need:

1. Aluminum foil

2. A plastic container big enough to fully contain the piece you want to anodize

3. 1-8 nine volt batteries

4. At least 4 feet of insulated wire

5. Borax

6. Hot water

7. A spoon

8. Rubber gloves

9. Acetone or alcohol (the alcohol swabs at CVS work well)

10. A plastic cup (should hold about the same volume as your plastic container)

Tools (optional):

1. Pliers

2. Wire strippers

Step 4: Method 1 - Using a Chemical Cell - Step 2

Time to mix your electrolyte and build the anodizing bath.

Take the cup, spoon, borax and hot water and combine in the cup. Mix until all borax is dissolved. The closer the mixture is to saturation the better.

For the anodizing bath, take the aluminum foil and completely line the container with the foil. If there is any excess foil around the top of the container, I recommend folding it around the edge of the container.

Step 5: Method 1 - Using a Chemical Cell - Step 3

Time for the wiring and battery setup.

Strip about half inch of insulation off both ends of 2 foot wire lengths. After the wires have been stripped, Take one corner of of the aluminum foil and make a hole through it. Insert the end of the wire and twist them together. Tuck in the wire and aluminum corner. Now fill with the borax and water solution.

Take the desired number of nine volt batteries and connect them as shown in the picture. Then connect the wire that is attached to the foil to the negative (-) terminal of the battery. Take the other wire and connect to the positive (+) terminal of the battery (this is the wire that gets attached to the titanium piece).

Step 6: Method 1 - Using a Chemical Cell - Step 4

Time to figure out what color to anodize. Different voltages will produce different colors. Note that you can always change the color buy increasing the voltage but can not revert back to lower voltage colors. The above image is for anodizing in sulfuric acid but the results are pretty similar with borax. Remember, if you are unsure of the voltage needed, just go up in small increments of voltage.

Step 7: Method 1 - Using a Chemical Cell - Step 5

Cleaning the titanium.

Put on your rubber gloves to prevent any fingerprints on the titanium after it is cleaned. Then wipe down the titanium piece with the alcohol until is it very clean.

Step 8: Method 1 - Using a Chemical Cell - Step 6

Now for the actual anodizing.

Take the titanium and positive wire and touch them together. Submerge the titanium piece. Make sure that the the wire isn't submerged and only titanium touches the solution. Also, take caution and make sure the titanium never touches the foil at any time. It can short everything out and generate huge and dangerous sparks. Once the desired color is reached, take the titanium out and dry it. You will find that some colors are affected by fingerprints and can become dull when exposed to fingerprints. This is perfectly normal and the original color can be restored using acetone or alcohol to remove the oils

Step 9: Method 2 - Using Heat - Intro

For this anodization method, intense heat is used to thicken the oxide layer. I use a gas stove to anodize but a blowtorch is recommended.

Step 10: Method 2 - Using Heat - Step 1

Gather your parts and tools.

You will need:

1. A heat source (blowtorches are best but a gas stove works too)

2. A pair of tongs or needle nose pliers (the handles will get hot so make sure they are rubber coated to provide adequate insulation)

3. Alcohol or acetone (alcohol pads from CVS work well)

4. A cup of very cold water

Step 11: Method 2 - Using Heat - Step 2

Clean the titanium as in step 5 of the chemical cell method.

Step 12: Method 2 - Using Heat - Step 3

Time to anodize!

Take the cleaned titanium and grip the edge of it with tongs/pliers. Turn on your stove/blowtorch and bring the titanium piece close to the heat. Keep the titanium moving and you should notice a color change to yellow after about 30 seconds or so. Heat the titanium piece for longer to achieve reds, blues and some greens.

Step 13: Method 2 - Using Heat - Step 4

After the desired color is achieved, turn off the stove/blowtorch and submerge the titanium in the cold water to cool it down. Be careful not to touch the titanium until it is cool as it will burn you. Same goes for the tip of the pliers/tongs too.

Step 14: Conclusion

Congrats you have anodized titanium!! I hope you found this interesting as well as fun and enjoyable. Please share your thoughts in the comments below. I look forward to any comments or suggestions.

Step 15: Troubleshooting

If anodizing the titanium isn't working for any reason, please ask me in the comments as I would be more than happy to take questions!

Here are some possible solutions to problems you may encounter:

1. Make sure the titanium is the only thing submerged in the solution. The wire touching the titanium must not be submerged.

2. Make sure the wire touching the titanium is connected to the positive terminal of the battery.

3. Make sure you are using borax. Sulfuric acid works well too but is very dangerous to work with.

4. Make sure your batteries aren't dead.

Comments

[noelle0526]

Please, DO NOT line the entire container with foil - that's dangerous! Only a small amount of foil is needed. It also allows you to let the piece rest at the bottom of the container while it's anodizing. Using a small piece of plastic mesh is a useful barrier between the foil and the part.

[Jason the Saj]

What is the purpose/intent of the alumin foil. Is it functioning as the cathode? Can you simply use a small bar of titanium? Or is the aluminum functioning as a catalyst?

[leo.hellberg]

Very nice! The picture at the end has a pen that seems to have a specific pattern. like plus signs or something. "Gold" and pink almost, and it also seems like some parts are glossy and some parts that are matte.. Would you mind giving a hint as to how this is achieved?

[fkunitz]

Thank you so much for the instructable! This way is SO much more vibrant than with my torch!

Just fyi for anyone else, 2 9v's gave me purple and 3 gave me blue.

[fkunitz]

My phone takes horrible pictures, so this does do them justice.

[Muhlis uzzaman]

Waw ini sungguh luar biasa mungkin hanya saya satu satu nya orang yang masih bodoh dalam anodizing titanium,

[Muhlis uzzaman]

Saya masih bingung tentang anodizing titanium saya pernh mencoba dengan menggunakan baking soda baterai 9v namun gagal ada yg ingin saya tanyakan dan saya berharap anda menjawab, air yang anda gunakan itu harus di proses dulu atau tidak?

[Robin Alden]

Hi.

Were in COVID-19 lockdown in New Zealand so I can't get a hold of any Titanium to anodize. I'd like to know the electrical resistance of anodized Titanium. Could you please measure the resistance of some of the Ti that you have anodised and let us know.

Thanks

Robin

[arunshantilalsoni]

What should be quantity of borax or sufuric acid ? Concentration ratio ?

[arunshantilalsoni]

Does color chart vary with titanium grade ?

[tampusrichie7171985]

how about on stainless steel? will it work on the same process and method? thanks.

[bpark1000]

Safety warning!

Watch out when heating titanium with a torch! If the titanium has thin sections, they can "light off" like magnesium! The burning metal can not be extinguished! If the burning metal is put in water, the fire will become more violent! Do this only outside.

Also use caution if you are connecting enough 9V batteries to get 100 volts!

If you "over anodize" (use too much voltage in the electrolytic process, and "miss your color"), you can reverse the connections to remove the anodizing, then switch back and use a lower voltage.

[JunD19]

Hi, I have a titanium eyeglass frame that i want to de anodize, does reversing connections work with it also?

[SHOE0007]

The titanium sheet from e-bay should work with a propane torch right? I am trying to expose titanium sheets (very thin sheets) to high temperatures 500-900 degrees C with a propane torch. I know that there are risks of fire but if you cut off the oxygen immediate if smoke starts then it is safer. The risk of fire as I seen on youtube is quite low --- but still a risk. Here what I plan to work with.

Titanium Ti Gr2 Thin Silver Metal Square Plate Sheet Foil Craft 100x500x0.1mm

[sfernan]

by any chance is anodizing with borax possible with aluminum instead of tita

[fkunitz]

No

[sfernan]

titanium *

[djmelvinv]

hi. awesme project. defenitly the indication spectrum. Like to make my own. I'm from holland and I just don't know what borax is. And can this be done with any metal like aluminium? Less expensive en easier to get.

[Steelsmith1]

From Wikipedia:

• Anhydrous borax (Na2B4O7)
• Borax pentahydrate (Na2B4O75H2O)
• Borax decahydrate (Na2B4O710H2O)

Borax is generally described as Na2B4O710H2O. However, it is better formulated as Na2[B4O5(OH)4]8H2O, since borax contains the [B4O5(OH)4]2−ion. In this structure, there are two four-coordinate boron atoms (two BO4 tetrahedra) and two three-coordinate boron atoms (two BO3 triangles).

I may be available in Holland from a supplier of clays and chemicals for potters. It is in the USA. It is available in the USA in groceries and used to help wash clothing

[djmelvinv]

haha so funny. I was better if I googled it first. I thought it was an brand but it is just a mineral. I'm gonna make an arduino with a colour sensor so it in will slowly increase voltage till the color is reached. (servo to pull it out.