He also included "synthetic transparent stones" which I took to mean zirconia.
I’m not sure about cubic zirconia . . .I’ve always heard that
they do not withstand heat very well. Yet, I have seen CZ’s
incorporated into lamped beads. I’ve often wondered how they did
that.
Remember this is not for the faint hearted or on stones that you
cannot afford to replace. I will only do this on diamonds myself
but have heard about doing it with CZ but I wounder why. Any
Questions just ask…Ron
Ron,
I’m confused. You WILL do this with diamonds?
Seems like CZ and syn. corundum would be the “stones” of choice
for this method. They’re hard, so they aren’t likely to be
crushed by the shrinking metal, and they are cheap, so it
doesn’t matter so much if you mess up a bit. Am I missing
something?
Tom
Oxidation plays a role in bimetal casting. While it would seem
that casting gold alloys around a niobium insert would work, it
doesn’t. One of my mentors regularly cast gold bezels in his
waxes- and ran a wax bead up the seam in the bezel wire. Worked
great, and it was a real time saving trick.
For some reason, I have trouble understanding why it is
important to cast stones into a casting. Remove the stone, cast
the piece, set the stone. It will probably look better, and you
won’t go through the agony of wondering if the stone will survive
the casting process. The setting time is shorter that the time
it takes to dig a casting out of cooled investment. The stones
that will survive the abuse of casting will probably survive
setting.
Rick Hamilton
Richard D. Hamilton
Martha’s Vineyard
USA
Fabricated 14k, 18k, and platinum Jewelry
wax carving, modelmaking, jewelry photography
For some reason, I have trouble understanding why it is important to cast stones into a casting. Remove the stone, cast the piece, set the stone. It will probably look better, and you won't go through the agony of wondering if the stone will survive the casting process.
hi rick,
the points you make about casting stones in place are accurate.
the attraction for me was just to do it, so i did once. the
reason large manufacturers cast stones in place is cost. in the
case of channel setting multiple rounds and baguettes, western
manufacturers can’t compete with cost of labor so they compete
technologicaly. a great wage in china is $40-70.00 per mo
according to a friend who does business there. that’s a lot of
set baguettes for $40-70.00.
however, i’ve repaired and tightened more of these stone cast
in place rings than i care to admit to. my opinion is, even
after careful modeling, ‘setting’, inspection and burn out,
these manufacturers still can achieve only a second to a stone
set after casting.
best regards,
geo fox
I agree with you Rick, the only advantage to casting stones in
place that I can see is if you are manufaturing large quantities
of inexpensive. low margin jewelry, it will save time. I dont see
how you could get a perfect polish under the stones. I think its
fun but doesn’t give you a better product.
Mark P
In that case you would probably be putting the stones in the
silicon rubber molds prior to wax injecting them. Clean up and
finishing by tumbling would probably diminish the production
rate. If it were really worthwhile, school ring companies like
Balfour would be doing it. They have all the latest technology
stuff- including CAD-CAM.
Richard D. Hamilton
Martha’s Vineyard
USA
Fabricated 14k, 18k, and platinum Jewelry
wax carving, modelmaking, jewelry photography
Clean up and finishing by tumbling would probably diminish the production rate. If it were really worthwhile, school ring companies like Balfour would be doing it. They have all the latest technology stuff- including CAD-CAM.
Next time you have a Stuller catalogue in hand, look at the
pictures. Trees with maybe a hundred models spruued for casting,
and look! Don’t those waxes contain stones? They aren/t Balfour,
but I’ll bet that they are turning out similar production.
Bruce D. Holmgrain
e-mail: @Bruce_Holmgrain
http://www.knight-hub.com/manmtndense/bhh3.htm
snail mail: 311 Sugarland Run Drive, Sterling, VA 20164
phone:: 703-593-4652
Coming in at the end of the thread he decloaked and said…
Balfour might do it but I don’t think they have the need.(I used
to work for T&C) Anyone who can accept the lower quality setting
job can make use of it. It is WORTHWHILE if done properly.
Would be interesting to know if they are doing that in production,
and really casting stones in place,or if it was done as a lark for
that photograph.
Richard D. Hamilton
Martha’s Vineyard
USA
Fabricated 14k, 18k, and platinum Jewelry
wax carving, modelmaking, jewelry photography
Hi Richard, Casting stones in place has been largely pioneered and
perfected by the folks at Romanoff in NY. My opinion is that it is
used for an edge on the bottom line for production folks. There
probably would be a creative case for it with diamonds. I wouldn’t
take the risk for myself with a nice ruby, but I understand the
process. Call Romanoff for more info at 800-2217448.
Mozeltov…J.A.
I’m not sure that they are using the processs but it is Real
Production Stuff,Rick
John/List … Casting stones in place has been around in secret (
Don’t forget … The Big Secret is … there is/are no secret(s)
) since the early eighty’s. I did it with CZ’s in 1982 on brass
alloy sample castings but found the quality of the final product
was not representative enough of the final product and did not
pursue it. Others were working on it at that time.
The issues are well developed. Methods have been described that
vary from simple ( stuff a stone in a pre-cut setting) to very
complex ( mount the stone in a rubber mold and shoot the wax around
it ) and everything in between. All have been successful and I have
practiced many of them. Understand the physics of the casting
process(es) and you’ll find all the answers.
Romanoff holds no corner on the knowledge base for this process.
See the Proceedings of the 1997 Santa Fe Symposium.
Paul Finelt
Paul Finelt
It would be a great process to develop for white metal casting- I
did help develop a process casting thermosetting resin around
metal inserts back in the early 70’s.
I do a balance of waxes and fabrication in my work, and few stones
besides diamonds would stand up to being cast in place anyway.
Tahitian pearls, tourmalines, color change sapphires? Well maybe
the sapphires. So casting in place has its merits for production,
especially with the synthetic stones that can stand the heat. I
understand the facination, however.
What have you done with casting colored alloys together?
Rick Hamilton
Richard D. Hamilton
Martha’s Vineyard
USA
Fabricated 14k, 18k, and platinum Jewelry
wax carving, modelmaking, jewelry photography
I am curious as to the method and procedure of stone in casting for
diamonds as well as color.
Thx, Don
I may be treading some peoples toes and if they dont approve of some
of my facts, they can correct me via email …but here goes the
method I use and teach when I set stones in wax!
I only set stones such as Ruby, Sapphires, Diamonds (any with
minimal inclusions) “Thou shalt not set or use any other kind of
stones”…The harder they are on the Mohs scale, the better…! Do not
wax set with stones less than 9.0. What I initially do is with a
simple round bur, size of the widest part of the pavilion hand rotate
the bur, so the stone will sit on the wax that is touching this
pavillion.
Let the stone sit “ON”, not “in” the wax impression. I use a blue
wax that is similar to plastic. That is, when you press the stone in,
the wax expands and allows the stone to feel its own level and then
the wax will return to its original position.
I also use a rheostat-heating model makers tool tip with a little
curved blade and then heat up the stone only enough to settle the
stone into the wax. The “sinking heated stone” will form a little
edge (Meniscus Curve) around the girdle of the stone, …the stone
will now displace some wax and “then this wax” when casted, will then
"hold" the stone…I have been asking casters around this city about
the temperature of the gold with stones in…they say drop the
temps. only 100-150 F. MAX.!!!
DO NOT RAPID-COOL AFTER CASTING, let the hot flask cool on cement
floor, or put it immediately back into the cooling furnace…I have
seen so many stones break and once, 10 carats of diamonds shatter
when the rapid cooling was attempted, a real ugly and expensive
sight. enjoy, enjoy!..I hope this helped you…Gerry!
Continue from:
DO NOT RAPID-COOL AFTER CASTING, let the hot flask cool on cement floor, or put it immediately back into the cooling furnace...I have seen so many stones break and once
I have only cast with diamonds in place a couple of times. A huge
error that I made one time was to set stones so close in a channel
that they actually touched. Slow cooling didn’t help them in this
case. I suggest that one leave a gap .1mm wide between the stones
for better results
bruce
Bruce Holmgrain
http://www.goldwerx.com
Well, big topic. I suggest you read
http://preciousmetalswest.com/stonein.htm
And similar articles that can be found in AJM. August issue from a
couple years ago.
In a nutshell, this is a mass production method, in general not as
well suited to designer “one off” pieces. The size of the setting,
prongs, channel, and all is critical to the size of the stones.
Shrinkage calculations must be right on the money. Ideally, Plan on
special alloy; low flow temp, high fluidity (high zinc at least) call
an alloy guy for more detail. Plan on a special investment or
additive to protect the stones. . Burnout never really happens, its
more like a “warm out” 
to be gentle to the stones. You must not
quench-stones hate thermal shock. Stone in place casting is one
reason lasers grew in popularity so fast. These stone in casting are
well worth fixing recasting is problematic cost wise. The best thing
stone in does to the average caster is to get all those niggling
variables controlled. Like precise measures of investment powder,
water volume and temperature control in every way. This makes all
the castings better.
Daniel Ballard
Don,
AJM magazine has published many articles on this technique over the
years. You can order copies of them even if you are not a member:
There is a $5 per article fee for non-members. You can order copies
via the Web site at www.ajm-magazine.com.
I don’t find AJM’s article index as easy to navigate as the older
version, but this is a sufficiently common topic you can use the
site’s “search by topic” feature, which will give you all the
articles since 1997. There were others earlier: if you need to track
them down, your best bet is to call an MJSA member service rep and
ask for their help.
Good luck!
Suzanne
Suzanne Wade
Writer/Editor
Phone: (508) 339-7366
Fax: (928) 563-8255
@Suzanne_Wade1
http://www.rswade.net
Hi,
An important point is that minimum wax (later transformed to metal)
must hold the stone securely from the top and bottom to reduce heat
transfer and keep open for good look.
If you do only small quantity, you may take the impression in wax.
If the stone is over 2.5 mm, the net shrinkage of about 1/2 to 1%
during casting – expansion of investment and reduction of metal–
matters.
Especially for larger stones, over 6 mm, you may not want to cast,
but make only a good seat to help set in metal. It makes sense to use
a Teflon tape below the stone and heat the stone with a small wax
solder pen to get a good seat. Then, you may remove the tape, stone
and clean the melted wax.
After casting, hardly any work will be needed to set.
Regards
Shishir Nevatia
Sunjewels
Seepz Mumbai India 400096
Fax +9122 2829 0206 or
+9122 5691 9739
When you cast in place, after the cool down, submerge in water and
re-vacuum under water. The investment comes out in slurry. This way
you don’t need to dig it out.