Hey! You also have the option to build a fairly inexpensive home anodizer and anodize one half - that gold colour looks to be about 55 DC volts. PM me if you want to know more, I can give you some resources and walk you through it.
Im pretty sure anodizing dose not work on titanium like it works on aluminum. Am I wrong? Otherwise this would be the way to go. … Aside from the “let’s make it hot with fire until it turns color method” … I don’t see that there is any other option.
Hi @Jedillama, you are right that anodizing titanium is different from anodizing aluminum. In both cases, an oxide layer is formed, but with aluminum, that oxide layer is then used like a primer to hold a colour dye. Where as titanium (and niobium and tantallum) create clear oxide layers that alter light refraction and can create different colours based on the thickness of the oxide layer. Heating titanium with a torch has the same effect as electrolysis where the titanium atoms are excited and bond to oxygen atoms to form a titanium oxide crystal layer. However, electrolysis is much more precise and exact colours can be formed by running a specific voltage through the metal. It is more finicky to get the same vibrancy of colour out of titanium as with niobium, but here is a voltage scale that I use for my niobium jewelry work and an example of two different bracelet colours.
edit: This scale applies directly to titanium as well.
So to get that gold colour I would say that a 55 volt current would be right about there.
Gotcha. That was a really informative post. Thanks for taking the time to put that together.
Thanks for the suggestion! I’m curious about the process but I’m worried I might get a color I’m not happy with - is the process of stripping a titanium anodize later intensive/abrasive?
I remember he used a variable power supply.
What you want is something that can go all the way to 100V, as some of the cooler, more vibrant colors are in the upper voltage (60V+). Though I think around 50V produces a gold color in titanium.
good to know, thanks.
Yes yes yes, a variable power supply is the best way to go because you can fine tune the voltage. But they are expensive. What I am currently using for my jewelry work is I connect 9 volt batteries in series to get the voltage that I want. It works for me but is less accurate and has less amperage, so it can be slower for larger pieces. Still the most budget friendly option to get your foot in the door.
I haven’t needed to strip anything… but yes there are options. There are commercial titanium etchers that will take anodizing off. It is also recommended to use these prior to anodizing to get brighter colours out of the titanium. But in my experience, a gentle jewelry polish will also gradually work away at it. The neat thing is it will go through the different colours as it gets thinner.