Hello!
I’m terrible at (and impatient with) research and could use some
guidance. I have a request for a purple titanium ring and I’m trying
to find out 1. At what temperature can I accomplish this using my
kiln, and 2. How well would the patina hold up on a wedding band
(worn every day)? The patina would be in recesses only.
Please point me in the right direction if you could.
Thank you!
Caitlin
Hi Caitlin,
I almost always color titanium electrically, so I don’t have a
color/temp map, but 15 min at 575C gives a pretty good blue/purple
wash on 1/8" Ti. Try it on a piece of scrap first.
Be aware that the colors you get by thermal oxidation are chemically
different than the colors you get from electrical anodization, and
Multi-Etch won’t erase them very well if you overshoot, or don’t
like what you’ve got. Thermal coloring is much more of a ‘once and
done’ sort of thing. (Turns out the thermal film is mostly nitrides,
rather than oxides as with electrical coloring.) Ask me why I know
this…
The biggest issue with a wedding ring (or any other daily wear item)
is that the color will wear off fast, even in the recesses. I
wouldn’t do it on a wedding ring.
Regards,
Brian
1. At what temperature can I accomplish this using my kiln, and
You would have to experiment. But you might find this difficult to
do with a kiln. Purple is not an “endpoint” in the coloring sequence,
but rather, is an intermediate color in the sequence of colors Ti
goes through. Getting a uniform exact color would require not only
precise temperature control, but precise timing too.
It would be much easier, give a more uniform color, and give you
much more precise control over the exact color you get, to do the
coloring via anodizing instead of heat. That means to connect the
ring to one terminal of a DC variable voltage power supply, the other
terminal is immersed in a suitable liquid electrolyte, and you
immerse the ring in that solution. The color you get is determined by
the voltage, and normally, one starts at a lower voltage, and dials
it up until you get the color you wish. If you miss, keep going, as
the color sequence repeats as you go up, though not indefinately (it
gets “muddier” as the voltage gets too high, then finally just
settles in on a durable darkish grey) The whole process is much more
controlable than heat coloring. You can even hook this up as a
paintbrush brush plating sort of thing, and paint with various colors
in the same piece, varying the voltage as you paint differing areas,
or you can get multiple colors via immersion anodizing by masking off
areas, anodizing at the highest voltage color you wish, removing the
mask, and anodizing at the lower voltage colors, which won’t change
the first higher voltage color.
While doing this does require some additional equipment, I’d say
this is the most versatile way to go. But first, try experimenting
with your kiln and see what you get on some scrap Ti. Who knows,
perhaps you’ll be able to control it well enough for what you wish.
2. How well would the patina hold up on a wedding band (worn every day)? The patina would be in recesses only.
The anodized surface of the Ti is reasonably durable, but not
totally so. Higher, exposed areas would wear away within a probably
unacceptably short time for a ring. Jewelry that takes less wear,
like pendants or earrings, would be quite durable enough. But you did
say the color is in the recesses. If they are deep enough to really
avoid the bulk of the wear, then it should hold up well.
Chemically, it’s inert, so you don’t have to worry about it changing
over time.
And just to keep the language consistent, you’re not applying a
patina. It’s an anodized surface, meaning an oxide layer induced by
applied voltage while the piece is made the anode in the electrical
connection. The voltage changes the thickness of the oxide layer, as
higher voltage forces oxygen deeper into the layer, which by itself
is an insulator and fairly impervious. If you color by heating,
perhaps you could call it an oxide or patina layer, but in both
cases, it’s the thickness of the oxide layer (which by itself is
transparent and colorless) which determines what color you see.
If you have little luck getting this to be controlled via heat, and
want to anodize but don’t have the tools, I’m certain you can find,
here on the list, any number of folks who’ll be happy to do it for
you (including me).
Peter Rowe
Seattle
Hello I would not use heat. I would anodized it. That would last the
longest.
Regards
Hartley
Caitlin,
The right direction is to turn round and walk away from this one.
Why? because oxidised titanium,
Is a surface oxide, and very thin.
Purple is the first colour on heating,
it is the least durable,
on a wedding band for every day use, will look lovely, like the
bride on her day, but a year later?
You will get it back for re polishing and oxidising.
Thats assuming in the first instance, youve the equipment to make
the band. You will need at least titanium bar stock and an engineers
lathe.
Do you have one? Its not something to make by hand.
Also have you worked out which grade of titanium to use? Ted who has
worked this metal since 1980.
If you take on this comission it will come back and bite you.
Hmmm.
I have a titanium wedding band and a titanium engagement ring. The
wedding band has purple in the carved grooves. 13 yrs later - still
purple and absolutely fine. And I am VERY rough on my jewelry. My
husband has a niobium/sterling wedding ring. Again - colors are just
fine. I can see the issues about having color on a surface of a ring
-Lori Who wishes she had the $$$ to make titanium jewelry and must
stick to 925, Cu and Brass
The biggest issue with a wedding ring (or any other daily wear item) is that the color will wear off fast, even in the recesses. I wouldn't do it on a wedding ring.
The other big issue with wedding rings is the expectation, fairly
well ingrained in our culture, that they will be there for the long
haul. A metaphor for the relationship.
That being said, I am on maybe my eighth or ninth wedding ring. 8/11
will mark 31 years of marriage. I’m not sure what ring Kim is on.
But being a metalsmith --or married to one–puts the wedding ring
thing in a slightly different light. At least around here.
Andy
I’d like to interject that there are two colors before purple. light
bronze, dark bronze. There is also a “high” purple that I get just
after fuschia, but before teal (roughly 80v on my anodizer setup)
with a thicker oxide than I get around 20v for the dark purple. Been
anodizing CP and 6Al4VELI Titanium for a decade and while the
fabrication info is true, the anodization is no big ideal with
proper preparation and technique.
Hmmm.
I have a titanium wedding band and a titanium engagement ring. The
wedding band has purple in the carved grooves. 13 yrs later - still
purple and absolutely fine. And I am VERY rough on my jewelry. My
husband has a niobium/sterling wedding ring. Again - colors are just
fine.
I can see the issues about having color on a surface of a ring - but
not in recessed areas. However, I have purple post earrings I have
been wearing almost daily since the mid-1980’s - still purple and
gorgeous. I have been “collecting” titanium jewelry since 1982 - I
have about 30 pieces. Only once have I had color “wear off”- and it
was in the green color family. The blues and purples have endured. I
got my wedding band from Dr. Daniel Statman.
-Lori
Who wishes she had the $$$ to make titanium jewelry and must stick
to 925, Cu and Brass
Hmmm.
I have a titanium wedding band and a titanium engagement ring. The
wedding band has purple in the carved grooves. 13 yrs later - still
purple and absolutely fine. And I am VERY rough on my jewelry. My
husband has a niobium/sterling wedding ring. Again - colors are just
fine. I can see the issues about having color on a surface of a ring
-Lori Who wishes she had the $$$ to make titanium jewelry and must
stick to 925, Cu and Brass
Hmmm.
I have a titanium wedding band and a titanium engagement ring. The
wedding band has purple in the carved grooves. 13 yrs later - still
purple and absolutely fine. And I am VERY rough on my jewelry. My
husband has a niobium/sterling wedding ring. Again - colors are just
fine.
I can see the issues about having color on a surface of a ring - but
not in recessed areas. However, I have purple post earrings I have
been wearing almost daily since the mid-1980’s - still purple and
gorgeous. I have been “collecting” titanium jewelry since 1982 - I
have about 30 pieces. Only once have I had color “wear off”- and it
was in the green color family. The blues and purples have endured. I
got my wedding band from Dr. Daniel Statman.
-Lori
Who wishes she had the $$$ to make titanium jewelry and must stick
to 925, Cu and Brass