I have found white gold rings to be particularly problematic when
sizing or repairing. Especially old gold. Hair line fractures and
breakage seem to be much more prevalent in the white. Any feedback
on this would be much appreciated.
Laverne
I have found white gold rings to be particularly problematic when sizing or repairing. Especially old gold.
Hi Laverne;
Yep, white gold becomes brittle with age, and 18K white is the
worst. If possible, you can carefully anneal the article (assuming
you can verify there have been no repairs with low temperature gold
solders). Heat to a barely visible red heat, allow the article to
cool to just below the red, then quench it in your boric acid/alcohol
solution. Yep, in the alcohol. Water or pickle will cool the article
too quickly. Of course, if you have stones that can’t take heat or
the thermal shock of the quench (as I know, only diamonds, and good
ones at that, can take that shock), you have little else you can do,
other than to proceed slowly and carefully and hope for the best.
Sometimes, you have to make slight cuts in the outer circumference
of a ring to create little “hinges” which you can later use 19K white
weld to fill. If a ring is going to end up egg-shaped, it’s
sometimes better for the customer to agree to live with that (explain
beforehand, of course) than to risk breaking areas that will be
difficult to repair should you try to completely round up the ring on
the mandrel. By the way, I prefer to size all white gold rings with
the 19K white weld solder, since that minimizes the likelihood of the
seam polishing out and leaving a line, but when in doubt, use the 14K
white hard, and 14K white easy where that’s all you can use. Lower
temperature solders for white gold tend to be yellow-er. Rhodium
plating will take care of that, although I seldom completely plate a
white gold article unless the customer requests it. I prefer to
just touch up solder areas with my pen plater.
David L. Huffman
I have found white gold rings to be particularly problematic when sizing or repairing. Especially old gold. Hair line fractures and breakage seem to be much more prevalent in the white. Any feedback on this would be much appreciated.
Laverne That is why high grade 18K white gold is no longer on the
open market. If your white gold is done right age has nothing to do
with it. Over heating and burning it is the cause from day one,
“crappy casting”.
This is a copy of a report I wrote up in 2001; people had problems
with the color of white gold and the rhodium cover up used to fool
the customer. This is a very interesting expose covering all that
platinum junk being done as well. Read on and you will know why your
white gold cracks, and platinum too.
I guess nobody likes the truth be known. This is a professional
report; Plating can be controlled by painting nail polish on the
parts that you don’t want to plate before dipping the item into the
Electro plating bath, usually a small beaker the size of a coffee pot
is used. Those brown spots are low voltage electric burns likely from
several rings at a time on the copper hook in the rhodium bath as the
hook is shaken around in the bath to expose all parts to get a good
coating. those burn spots are where the rings shorted out (ouch).
I have been a top jewelry craftsman for 40 years. I know exactly
what you are all going through, and this is the reason the jewelry
business is struggling with this problem. White gold is the poor
man’s platinum look. Money is the problem, it costs too much to use a
good high grade nickel content to be bright on it’s own.
Because we can only re-melt white gold 2 times to be safe as the
nickel inside the white gold becomes very brittle when over heated
and gives lots of problems during fabrication, cracking (referred to
as dry gold) and then there is pin holes, air pockets caused from
over heating where oxygen is left in the metal as it is cast.
Jewelers hate that as they have to block them up to get a job out as
they usually pop out at the last minute when the job is all finished,
and then there is what we call frosting (hundreds of tiny tiny air
holes in groups that leave a dull spot that never can be brought up
to a shinny surface) When casting parts we must use more gold than
necessary then the scraps (trimmings) are used to melt again for
another cast, usually they should try to go half used gold with half
fresh gold that is to help tenderize the mix so as to try to avoid
cracking gold. (Sound familiar)
Why do claws fall off a diamond with hardly any force? Some people
buy old gold and even dump it in to the pot and prey that it works
out. (Not knowing how many times it was melted when it was made say
30 or 40 years ago and then you end up with a patched up mess of a
job) Because the gold was melted too many times or was over heated
right from the start, that makes the gold brittle, I have seen claws
that were holding on by a prayer that I could crack off with my
fingernail. It is a big cover up as they know what the problem is
but can’t afford to use fresh gold every time. The half way effort is
to lower the nickel content to tenderize the gold, hence the
yellowish white gold that has to be rhodium plated to cover it up.
Cartier of Paris started a trend oh 30 years ago where they set
their diamonds in 18K yellow gold trying to convince people that it
was a style, but I knew exactly what the reason was that they started
that. It was to avoid going to white gold, as they didn’t always use
platinum for cost reasons. You see 18K yellow gold is like butter it
never cracks when working with it, it is alloyed with copper and
silver, both very soft malleable metals, The nickel used to alloy
white gold is the same as in stainless steel that is why it is very
hard to work with
The jewelry store sales people would not know anything about this.
Platinum is also a big problem these days as every body is casting
things they shouldn’t be doing, just to follow the trend, a lot of
platinum castings are cracking as the metal was not hot enough when
cast (Platinum is different it cannot be burnt you could sit on it
with a big welding torch for a whole day at over 3,000 degrees and it
would only get more pure and more beautiful, There is also the
problem of people buying old platinum jewelry to get platinum at a
bargain, then sometimes if that was platinum with some
contamination85 then bingo there goes the whole lot when it is mixed
in, and that is another way where you may find cracking appear as
well.
But the shops that are out there are greedy as anybody would be, and
the process to cast items is overloaded by putting too many pieces in
each cast. A good cast should not go over 1 or 1 BD ounces of
platinum to be abl e to blast the hell out of it so it comes out
tender and good to work with. But the society we live in says hey we
could get more in and I’ve known some to go for 3 or 4 ounces at a
time, the result is the temperature at the center of the melt is not
consistent and by the time the metal gets into the cast some parts
are not hot enough, and those parts give trouble such as cracking (we
call it crumbling) Hey it happened to me too “that” is how I know.
Even small amounts like I did if not heated enough cracked and had to
be re processed at a higher heat.
Platinum in it’s real use should be hand wrought to be at it’s best,
but under the pressure of the cost of living short cuts are used. Hey
the same goes for the big carmakers these days a lot of junk is out
there in the name of cost. Now we see that the batteries in the smart
bombs were no good, but were told to pass them in the name of
profits, now there is a case where it looks like that may be the
reason the solders were killed by friendly fire.
Only the rich have the access to the (possibility) of getting the
real thing, if they know the right guy that knows what he is doing
and not just talking. Walk the walk and talk the talk. Hope you
appreciated my effort, but I cannot change the world alone.
Allan Creates Perfectly Fabulous Fit Arthritic Shanks P.O. Box 51 Cote
St-Luc Montreal Quebec Canada Tel: 514-488-7553 Fax: 514-489-7299
Superringfit.com
Of course, if you have stones that can't take heat or the thermal shock of the quench (as I know, only diamonds, and good ones at that, can take that shock)
Boy, David. you live on the edge with that one. While you’re right
that in theory, a good clean stress free diamond can be quenched, I
sure wouldn’t get in the habit of recommending anyone look at a piece
and decide the diamonds in it can withstand quenching. I remember it
being done as a demo at GIA, once, but that stone was small, and was
literally flawless, and they were careful even of the direction in
which it entered the liquid. We’ve all accidentally quenched
diamonds now and then in a careless moment, I think, and usually
heaved sighs of relief when indeed they did survive. But I’ve seen
just enough such situations end up with a cracked diamond that I
don’t think I’d want to do that intentionally at any time. In the
situation you describe, annealing without liquid quenching can still
be effective. Instead of the liquid quench try compressed air. It’s
a lot gentler (about like the heat of your torch flame on the
diamond, only in reverse, temperature-wise), but will still chill
the gold quickly enough so you’ll get some softening. Slow cooling
the white golds will allow age hardening to start to occur, but even
if that happens, annealing the thing will at least remove stresses in
the metal, and even if it’s hard, it becomes more workable.
Peter
Hi Peter;
you live on the edge with that one. While you're right that in theory, a good clean stress free diamond can be quenched, I sure wouldn't get in the habit of recommending anyone .
Well, I didn’t exactly recommend quenching diamonds and I don’t. I
just brought it up as a hypothetical. Sometimes I offer too much
But really, I may not pay too much attention when it’s
a .02c single cut, but no, I’m not in the habit of quenching
diamonds. I just hate to lose money. Get away with it 20 times,
then number 21 snaps and costs you enough that you are kicking
yourself. If you work as I do, with several jobs in process at once,
you just pick up the other article to work on while the other cools.
Sometimes, I just blow on them untill I’m blue in the face. But you
bring up another good point I left out. You don’t actually have to
quench white gold to achieve some level of annealing. But from my
experience, unfortunately, even quenching these old white gold
articles doesn’t seem to anneal them appreciatively. Tell, me, do
you suppose holding them at a specific temperature for a period of
time would work or who that, in fact, encourage re-crystalization?
Instead of the liquid quench try compressed air. It's a lot gentler (about like the heat of your torch flame on the diamond, only in reverse, temperature-wise), but will still chill the gold quickly enough so you'll get some softening.
This reminds me, in one place I worked, we had those little nozzles
with the thumb button like dentists use to blow moisture away around
a tooth their working on, etc. They were great for both cooling off
hot articles and blowing metal chips away when you’re cutting a seat
for a stone. If anyone knows, off-hand, where to get those,
assuming they’re still made, I wouldn’t mind having one again.
David L. Huffman
Peter & David, The alchohol quench is something I have done for a
long time also…Never had a problem with diamonds.
Mark
Hi All,
Just a little trick I’d like to share that many of you probably use.
When sizing a ring down that has a lot of spring to it I avoid the
risk creasing or cracking the sides when bending the shank by using an
adjustable wrench to squeeze closed the ring and hold a tight joint
while I solder.
I cut the shank to size, trim the shank so it will join tightly,
bend the shank only a little to help shape the bottom and then place
the ring inside an adjustable wrench. I then gently close the bottom
joint with the pressure of the wrench jaws. With the seam closed
tight the shank can be soldered with heat from either inside and/or
out. Vice grips work also but I prefer an adjustable wrench with
smooth parallel jaws.
Mark
Peter & David, The alchohol quench is something I have done for a long time also...Never had a problem with diamonds.
I got to thinking about quenching diamonds after sending my last
post. You may well be correct that it’s a lot less risky quenching
diamonds in alcohol than it is to quench in water. An alcohol
quench is a good deal gentler, since the vapor layer formed (as
happens also with a water quench when things are hot enough) doesn’t
let the liquid actually touch the diamond or metal surface until it’s
a good deal cooler than is the case with a water quench. So there’s
significantly less heat shock, which of course is also why it’s
better for brittle metals like white gold or rose gold. The same
could well be true for diamonds. Still, until I find a strong reason
to start taking risks, I’ll stay with just not quenching diamonds of
any significant size. melee set in something, well, that’s
different, especially when they’re my melee and would easily be
replaced if broken.
Peter
But from my experience, unfortunately, even quenching these old white gold articles doesn't seem to anneal them appreciatively. Tell, me, do you suppose holding them at a specific temperature for a period of time would work or who that, in fact, encourage re-crystalization?
there may be some lower than normal annealing temperature where
holding it there for a while would give you softening. it would have
to be still above the temperature at which age hardening occurs.
But i don’t know for certain. what i do know is that there seems to
be a good deal of variability between different white gold alloys as
to the way each is best annealed. Some of them, especially the high
nickel super white alloys are just a royal pain in the rear to
anneal. Nice white color, white enough they don’t need rhodium to be
white, but hard and nasty to anneal, or set stones in. After years
of mostly using an alcohol quench with white golds, I’ve recently had
to work with some of the 18K super whites where no matter what I did,
it wouldn’t anneal well enough to make our diamond setters happy. So
I started water quenching these things, and I find if the metal is
still almost glowing, or just barely no longer doing so, with a water
quench then it’s significantly softened. This, of course, goes
directly in the face of all the advice not to quench from too hot or
it will crack. In doing this (with the line of items my employer
makes in 18K superwhites), i’ve yet to have one crack from quenching
hot, in water. Since these are new castings, it’s not much risk, as
we can always scrap it and cast another if it cracks in quenching,
and getting it soft enough for the setters is a priority. At the same
time, I’ve seen several cases where other white gold alloys almost
shattered from that treatment, and needed the gentler alcohol quench
to survive. At this point, I’m no longer willing to say there’s any
one recommended and always effective way to anneal white golds. Try
the gentle way first, and if the metal is still too hard, choose
whether to get more aggressive. With many of the old die struck
items, remember that there is often solder holding various parts
together, a factor in whether you dare anneal at all.
By the way, a phrase in your question deserves clarification. All
annealing involves recrystalization. That’s the nature of the beast.
What differs is just how the new crystals reform, and with what
compositions. These are complex alloys, and usually are formed of a
mix of several types of crystal compositions, each often some partial
solid solution of two or more componants of the alloy. What changes
when you quench or not, or hold at higher temp, or cool slowly, etc,
is the percentages of those solid solutions, and the degree of
segregation of the differing types of crystals vs. a homogeneous mix
of everything. It’s that differentiation into different crystal
compositions which causes the age hardening, and this generally
occurs during cooling phases, not during prolonged heating. What
prolonged heating sometimes does is to allow the original (cold,
hard) composition to recrystalize into less stressed and hopefully
more homogeneous structures at lower temperatues than required if
only quickly annealing, thus minimizing problems with oxidation, and
excess crystal growth. The latter is not desired since growth of the
new crystals during annealing into fewer and larger crystals lessens
the strength of the metal…
Peter