Maybe this is a dumb question but with all of the interest lately in
less expensive alternatives to the “standard” precious metals, has
anyone tried to set opals in titanium? Bad idea? Titanium too hard?
Also, what is the most ruthenium you could blend with the titanium
and avoid too brittle of an alloy?
What flux do those of you who work with titanium use? A patent I
just read from the '60s suggests a mixture of sodium chloride and
potassium chloride. The free halid reacts with the titanium when it
is in the molten state.
Have not had the pleasure of trying to set opals, etc into Titanium.
If I had to do so I think I would find a way to design the setting
so it could be assembled in such a way as to set the stone.
Mechanical assembly or laser assembly in such a way it captures the
stone securely, rather than attempting to push Titanium onto a stone
firmly, would seem to be the safest method, to me.
To the best of my knowledge, nobody’s doing their own alloying of Ti
at a studio scale, so mixing in Ruthenium isn’t practical. (Ti must
be melted either in inert-gas or ultra-high vacuum. Not studio scale
techniques.) Annealing it properly requires the same sort of rig, so
rolling your own sheet isn’t all that practical.
You can’t really solder it either. Those 60’s salt fluxes were
aerospace industrial kludges before TIG welding really got off the
ground. The good news is that there are small benchtop micro-tigs
that’ll handle Ti very well in jewelry scale items. I’ve got a PUK 3
that does a beautiful job with Ti and Nb, and my understanding is
that the other pulse-arc micro welders all do them well. Lasers do a
great job with Ti as well. (Not so much on Nb, in my experience.)
So, with one of those, you could fabricate yourself a bezel, and set
a stone, but I don’t think I’d rush out there to try an opal first.
You can do bead setting in Ti and Nb, I’ve done it. Not my idea of
fun, but it is possible. (Bare handed even. No gravermax.) If you had
a welder, you could probably cook up some sort of weird setting to
hold an opal, but it’ll require some serious scheming.
Opals set in Ti are possible if you are very good and accurate, but
it might be cheaper to use fewer opals and 18K.
If you are going to mix your own Ti alloys I suspect that mastering
the high vac induction furnace needed is going to be more difficult
than the alloy mix.
Flux for Ti ??? Soldering in a high vac is not easy (see above
thoughts). Laser welding under argon works but doesn’t need flux.
I work with Ti infrequently these days, and am not an expert, but it
is not all that difficult. Don’t light it on fire (REALLY DON’T),
and have respect for the voltages needed to anodize. And the
traditional chemicals needed to get a nice surface etch are on the
severe bad end of my nasty list.
Opal set in Titanium I think is not a good idea… although if you
can make two plates cut out with a outer rim that you could rivet
the Titanium holding the opal in place, kinda hard to explain but I
can email you a scetch if that helps.
Don’t know if this would work, but suppose you could drill a precise
hole in the titanium, one that would almost allow a piece of 18
karat heavy walled tubing to be set down into it, but so close to a
fit that if you put the tube in the freezer and heating the titanium,
you could slip the tube down in the hole and as the titanium
contracted it would lock the tube in place, with a millimter or so
protruding above the surface of the titanium. Then you’d have a bezel
in which to set your opal. Drill the hole deeper than needed, and put
a spacer in the bottom to lift the opal up to the desired height.
That way, you’d have sufficient contact between hole and tube to keep
it locked in place.
or, for that matter, make a bezel with a bottom on it, solder on a
wire to the bottom, drill a hole the size of the wire through the
titanium, countersinking it where it comes through, and using the
wire protruding from the bottom of the bezel, rivit it in place.
You’d have to put a punch that fit inside the bezel in place to back
up the rivit, sort of as an anvil.
By the way, a pulse welder or laser does a pretty good job of
welding titanium to gold, as long as you’ve got the shielding gas on.
suppose you could drill a precise hole in the titanium, one that
would almost allow a piece of 18 karat heavy walled tubing to be
set down into it, but so close to a fit that if you put the tube in
the freezer and heating the titanium, you could slip the tube down
in the hole and as the titanium contracted it would lock the tube
in place, with a millimter or so protruding above the surface of
the titanium.
This sounds like a great idea and I’ve heard some variations on it
over the years but reading this morning, it hit me that if you heat
the pierced metal, the hole size would actually become smaller as
the bounding metal expands. I’m puzzled, to say the least.
This sounds like a great idea and I've heard some variations on it
over the years but reading this morning, it hit me that if you
heat the pierced metal, the hole size would actually become smaller
as the bounding metal expands.
This is a very old misconception that a little thought will resolve.
Imagine a sheet of metal with a circle drawn on it and heat the sheet
to make it expand. What happens to the circle? Does it get smaller?
No, of course not; it expands as the metal it’s drawn on expands. Now
imagine cutting the circle out with a very thin saw, and placing it
back in the hole. Heat them both (the sheet and disk) and watch them
expand again. Do you really think the disk will expand while the hole
it used to occupy gets smaller? Think about it.
it hit me that if you heat the pierced metal, the hole size would
actually become smaller as the bounding metal expands
I’ll jump in here, as I just answered this same question on another
forum! Think of expansion as being like an explosion in slow motion.
Everything moves outward from the center. If there is an empty space
at the center, the empty space expands too, as everything around it
moves out from the center.
Nothing moves against the “current”. So the hole gets larger, not
smaller.
I'll jump in here, as I just answered this same question on
another forum! Think of expansion as being like an explosion in
slow motion. Everything moves outward from the center. If there is
an empty space at the center, the empty space expands too, as
everything around it moves out from the center. Nothing moves
against the "current". So the hole gets larger, not smaller.
Well, my memory was of hearing that heated molecules move randomly,
in every direction. I don’t remember learning about a “current” or
“explosion” that would order the direction molecules take on regular
run-of-the-mill heat application. That’s why I figured that if the
circle were cut out of the center of the sheet there would no longer
be a resistance to molecules moving in that now unbounded direction.
Seems my long distant physics class wasn’t a total “take” and my
faulty remember-er and figur-er have led me into a popular
misconception. That I spoke without what would have been a simple
search for the facts was my own failing.
Thanks, Gary and Noel for putting me straight.
And David, in no way was my query a challenge to you or your
suggestion. Your description simply put a question into my mind and I
asked it.