shattered rose gold
abrasha
>
> I need help! Our shop cast a ring in 18K rose gold, using David Fell fine
> gold and rose alloy. No scrap or buttons. Cast at 900 degrees. After
> soldering the head and quenching in Sparex, the ring shattered! Huge big
> cracks running through the entire ring, the surface looks like a broken
> window pane. We need to remake the ring, but don't know what went wrong.
> Anyone out there know what went wrong?
> Marggi
Well first of all, you should never ever quench ANYTHING in Sparex or any other
acid or acid substitute.
This is so basic, I am not even going to explain why!
Furthermore, rose golds and/or red golds should not be quenched in water either,
but rather in denatured
alcohol.
Abrasha
http://www.abrasha.com
PHILLIP PRATT
annealed once, there should be no future problems handling the piece. He is
recomending that we premix our alloy and gold, then remelt for casting. At
that point, the gold will be heating for the second time and the ordered
structure will not form. My reading of your advice is that any time the gold
is reheated, it will need the same pampering. We have talked the customer
into 14K, and will take all due precautions, so the discussion is for future
reference only. Also, if we re-alloy the 18K with fine silver to make 14K,
will there be any rose color left or will we have made 14K color? Thank you
for all your help.
Marggi
>
>
>The solutions, fortunately, are fairly simple. You anneal rose golds by
heating
>them to a barely red temp. Let them cool just until the red is gone, and
then
>quench. But not in water or pickle. Quench them in alcohol. It cools
then
>quickly enough to avoid the ordered array structure or age hardening
effects,
>but not so quickly as to shock them and crack them. So long as you pamper
the
>alloy correctly during these heating/annealing steps, the alloy once cooled
will
>be quite workable. Note that the cautions about quenching in alcohol apply
as
>well, to quenching after you've soldered these alloys or an item containing
>them.
>
>
>
>
>Hope this helps.
>
>Peter Rowe
>
Peter W. Rowe
<PHILANDno...@worldnet.att.net> wrote:
>>We have one jeweler who is of the opinion that after the rose gold has been
>>annealed once, there should be no future problems handling the piece.
He's somewhat wrong on that count. Any time you have the metal above it's
minimum annealing temp, the atoms become mobile enough to rearrange themselves.
The ordered array structure can form any time the metal cools slowly enough to
allow it. The rate of cooling through that range from about 800 to maybe 550 or
so is the critical section that will determine how much the metal age hardens,
as well as forming that nasty ordered array. If you are actually working the
metal, such as rolling or drawing it, the risk becomes somewhat less, since in
working the metal and deforming the crystal structure, you force it to then
recrystalize in smaller crystals (also called a smaller grain structure) when
it's annealed. This structure is intrinsically stronger, so even if it does get
some of that brittle structure forming, it will be less liable to crack later.
But annealing a casting does not induce a smaller grain size. In his defense,
though, a casting cooling in the flask before being quenched is cooling much
more slowly than one just cooling after soldering, in air. So the problem of
induced brittleness IS indeed most severe in the initial cooling of the casting,
and IS less severe later, during soldering work, since air cooling a piece after
soldering is still cooling it considerably faster than cooling a cast flask.
So while he's perhaps correct in practical terms, that once properly annealed,
the casting will be LESS likely to exhibit problems, it's still not immune. The
best insurance is to be sure you simply don't allow rose gold to slowly cool.
>> He is
>>recomending that we premix our alloy and gold, then remelt for casting. At
>>that point, the gold will be heating for the second time and the ordered
>>structure will not form.
Nonsense. crystalizing from a melt is the same whether it's the first time the
alloy components are solidifying, or the hundredth, with the exception that each
time you remelt the alloy, you'll probably be burning off any more volatile
componants, such as any deoxidizers David Fell may have included in his alloy.
There may be practical advantages to alloying up a larger amount, which then
makes melting again during casting quicker and easier. And it better insures
that you've completely mixed your alloy. But every time you melt a casting
alloy, you'll introduce impurities like oxides, carbides, various dissolved
gasses, and the like. And you'll volatilize some of the componants if any
happen to be lower melting metals or additives. The molten metal has no memory
for it's structure or lack of it prior to melting. Any ordered array structure
that existed prior to melting disappears. And when cooling again, it's just as
likely to form on subsequent melting operations. This is not something that is
peculiar to only the first time the alloy is prepared.
>> My reading of your advice is that any time the gold
>>is reheated, it will need the same pampering. We have talked the customer
>>into 14K, and will take all due precautions, so the discussion is for future
>>reference only. Also, if we re-alloy the 18K with fine silver to make 14K,
>>will there be any rose color left or will we have made 14K color?
There really is no ONE 14K color. but adding fine silver like that will be a
yellow, not a rose gold. The exact shade also depends on deoxidizers like zinc,
and the precise ratio of copper to silver. I personally like the color of the
alloy of equal parts silver and copper, without zinc. (for fabricating, not
casting). The lack of zinc makes it brighter than most commercial 14K.
Commercial 14K "yellow" alloys can range from slightly more silver than copper,
to over twice as much copper than silver. Obviously, that's more rosey colored.
But even a little bit of silver quickly tones down the rose, so by the time
you've got one third silver and two thirds copper, it's a mostly yellow color.
I'd suggest trying small amounts to figure the color you want. Keep records of
how much and of what, you add to get it. A small amount of brass (which is
usually about 30-40% zinc, the rest copper) can be used to add the zinc
deoxidizers if you wish a classic casting alloy. The normal amount of zinc used
is usally about 5-6 percent of the total 14K alloy.
Get out your calculator to figure just what to add to your alloy to get the
results you wish (grin)
Peter
Mike S
I found some old 10K rose gold rings that I have melted and rolled
out. Then I've been fusing and reticulating this sheet to sterling,
and air cooling. Havn't run into any of the problems discussed here,
and I'm not altogether sure why. The color of the two metals together
is great.
Cheers,
Mike S.
http://home.earthlink.net/~stevens4000/
PHILLIP PRATT
From what I understand, the problem arises from casting in 18K, and a
particular molecular arrangement that happens when the atoms of gold are
allowed to allign with the copper atoms. In 10K, the allignment would happen
only randomly, because the ratio of copper atoms to gold atoms is not so
nearly equal. And when rolling, the crystal structure would be broken up
anyway, so there is very little chance of running in to this problem. I had
worked for years with rose gold, but only in 10K and 14K, with never a
problem. That's why I was so suprised when the 18K reacted as it did.
Reticulated rose and sterling sounds like a very cool texture. What are you
making it into?
Marggi
Mike S wrote in message ...
Mike S
<PHILANDno...@worldnet.att.net> wrote:
>Reticulated rose and sterling sounds like a very cool texture. What are you
>making it into?
>Marggi
It is going mostly into rings and earrings. It seemed like a very
economical use of a limited amount of gold. I'm pleased with
the color, because I've had bad luck trying to use 14K yellow
over silver -- you can hardly see a difference between the two
colors. What I should have done is alloy a bit of extra copper
into it. Oxydizing the silver increases the color differences even
more, or course. There are pictures of some of the rose gold
stuff at the "new works" link at my site. Unfortunately, for those
pictures, I ordered one of Kodak's picture floppies instead of the
picture CD, and the pixel resolution turns out to be w-a-y down from
the CD's. I will be retaking the shots soon. The CD's are
definitely worth the couple of extra bucks.
Daniel Conlin
doesn't know why this is self-evident. Aside from the obvious risk to
clothes from spattering acid (which doesn't really concern me) is there a
problem for the metal being so quenched?
abrasha <abr...@abrasha.com> wrote in message
news:pqimiscsjajph907i...@4ax.com...
Peter W. Rowe
<som...@mesquite.freeserve.co.uk (DOTHERE)> wrote:
>>OK, I've held off for this long, but it seems that I'm the only one who
>>doesn't know why this is self-evident. Aside from the obvious risk to
>>clothes from spattering acid (which doesn't really concern me) is there a
>>problem for the metal being so quenched?
It's not the metal, really. It's mostly safety. You may not care about your
clothes, but why waste them? And splash a bit of pickle in your eyes, and
you'll find yourself much more careful with it in the future. Plus, the
splashed pickle will rapidly rust things, damage wood surfaces, and other such
easily avoidable ills. It also puts a fine mist in the air, which you then
breath, more than you would just from the steam from the hot pickle pot. And
finally, if you happen to be quenching anything with cavities, hollow
constructions, or even casting porosity, quenching causes the pickle to be quite
thoroughly drawn into those cavities and pores, from which you then must be more
careful to clean it afterwards. And the kicker is that there's no real
advantage to quenching in the pickle, vs. quenching in water (or with rose and
white golds, alcohol) and then transferring to the pickle. Why take the risk?
Peter Rowe
Ron Arney Sr.
> news:pqimiscsjajph907i...@4ax.com...
> > Well first of all, you should never ever quench ANYTHING in Sparex or any
> other acid or acid substitute.
> > This is so basic, I am not even going to explain why!
Daniel Conlin wrote:
>
> OK, I've held off for this long, but it seems that I'm the only one who
> doesn't know why this is self-evident.
<Snip>
Wrong, wrong, wrong. You are not alone. I've been making jewelry a long, long
time, but where Abrasha is formally schooled I am, for the most part, self--
taught. Therefore, when Abrasha cracks wise with such remarks, I am no less
intimidated than you.
So tell us Abrasha, aside from screwing up a couple hundred dollars worth of
Rifflers and such, why souldn't we quench in pickle?
Ron
abrasha
With all due respect, I repeat this is so basic and plain stupid, I am not going
to explain why.
Formal schooling has nothing to do with it. Ask Peter, he has more patience for
this kind of stupidity than
I.
Abrasha
http://www.abrasha.com
Mike S
wrote:
I occasionally quinch in pickle when I'm also in electroplating mode.
That means that I have on a full face shield, plastic apron with arms,
and rubber gloves.
You might be able to get away with it, using safety pickle, with just
the full face shield, if you don't mind an occasional acid burn. But
you don't want to spatter nitric, hydrochloric, or sulphuric acid
anywhere on your body.
Cheers,
Mike S.
Charlie M.
your shirt and pants, splash in your eyes, ruin the top of your work bench
are others. It doesn't damage your work piece.
CharlieM :o))
"Ron Arney Sr." <rar...@elpn.com> wrote in message
news:13vgjsc4s2s3kukir...@4ax.com...
> > abrasha <abr...@abrasha.com> wrote in message
> > news:pqimiscsjajph907i...@4ax.com...
> > > Well first of all, you should never ever quench ANYTHING in Sparex or
any
> > other acid or acid substitute.
> > > This is so basic, I am not even going to explain why!
> <Snip>
>
> Daniel Conlin wrote:
> >
> > OK, I've held off for this long, but it seems that I'm the only one who
> > doesn't know why this is self-evident.
>
> <Snip>
>
> Wrong, wrong, wrong. You are not alone. I've been making jewelry a long,
long
> time, but where Abrasha is formally schooled I am, for the most part,
self--
> taught. Therefore, when Abrasha cracks wise with such remarks, I am no
less
> intimidated than you.
>
Fishbre396
<char...@ptialaska.net> writes:
>Ron, I believe your ruined tools is a pretty good reason not to. Holes in
>your shirt and pants, splash in your eyes, ruin the top of your work bench
>are others. It doesn't damage your work piece.
Holes in clothing??? I've always quenched in sparex . . . but I have always
kept the sparex in a crock pot, away from my bench top (I have a separate
soldering area) and I've never had "splash back" . . . perhaps, it's only
because I only have a few inches of liquid in a relatively large crock pot.
Ron Arney Sr.
"Charlie M." wrote:
>
> Ron, I believe your ruined tools is a pretty good reason not to. Holes in
> your shirt and pants, splash in your eyes, ruin the top of your work bench
> are others. It doesn't damage your work piece.
"It doesn't damage your work piece." Well now there is an issue deserving of a
good thrashing. Depends on the work piece, and what you mean by damage. If I
am working with store bought sheet and wire there may not be much of a problem.
But when I am working with sheet and wire I've rolled and drawn from ingots
I've cast from grain and clean bench scrap, quenching in pickle is definitely
a bad idea. With the passage of even a very short period time evidence of
porosity not visible to the naked eye will be revealed. Gives even good work
a bad case of the uglies, and the cost of the labor and lost time involved in
the remedy has to be charged off to no one but me. Worse, for me, if it is a
piece a patron is standing there waitng on, it may get out of the shop before
the uglies make their presence known, and that can do damage to the reputation.
I was hoping for Abrasha and others to perhaps reveal some of the more arcane
reasons for not quenching in pickle.
Ron
Ron Arney Sr.
abrasha wrote:
>
> "Ron Arney Sr." wrote:
> >
<Snip>
> > So tell us Abrasha, aside from screwing up a couple hundred dollars worth of
> > Rifflers and such, why souldn't we quench in pickle?
> >
> > Ron
>
> With all due respect, I repeat this is so basic and plain stupid, I am not going
> to explain why.
>
> Formal schooling has nothing to do with it. Ask Peter, he has more patience for
> this kind of stupidity than
> I.
>
> Abrasha
> http://www.abrasha.com
Yeah, I know. But what is obvious to you may not be obvious to all. To wit:
I missed your point, which, if I read you correctly is: Anything that makes an
idea dumb, makes it a dumb idea altogether.
Ron