Platinum & Gold work

Ok, here’s my dilemma. A friend of mine who heard I do some minor
jewelry work has just asked me a tough theoretical question that I
have absolutely no technical background or knowledge in working, so I
have no idea if its even possible. The problem here is that the ring
he designed for his soon to be fiancee is both a engagement ring and
a wedding ring, with the core in platinum and the surrounding in gold
(yellow).

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+=platinum g=gold
Side view

Now, the problem is he wants to give the platinum ring as the
engagement ring, set the majority of the stones in it, then
before the wedding covert the ring to the above rough design.
The idea is fairly novel, and I think it may be possible though
beyond my scope, and given the melting temps of the two
materials, he at least picked the core of the design with the
higher melting point, and I know you’d have to rework the stones
prior to adding the gold, but how to add the gold and ensure
that the two materials won’t split later?? Cast the gold onto
the platinum? Like I said, I have no idea if its even possible
and maybe I’m nuts for even asking about it. I have seen rings
similar to this but I have no idea how they were made. Maybe
using gold (white) and gold (yellow) instead of platinum and
gold (yellow)?? Any ideas would be greatly appreciated, as well
as anyone who might be brave enough to tackle this, its way
beyond me unless there’s something really simple I’m
overlooking. His heart is pretty set on this design if its
possible, and I’d really like to help him, so I turn to you.
Thanks for any help//

Ryan Comer, (@Ryan_Comer)
Comer Designs LTD.

Ok, here’s my dilemma. A friend of mine who heard I do some minor
jewelry work has just asked me a tough theoretical question that I
have absolutely no technical background or knowledge in working, so I
have no idea if its even possible. The problem here is that the ring
he designed for his soon to be fiancee is both a engagement ring and
a wedding ring, with the core in platinum and the surrounding in gold
(yellow).

If the stones are diamonds you could solder the two shoulders to
the platinum core without problems provided, of course, you clean
them carefully (and they are not fracture filled stones). Or talk
him into two loose rings, one for either side- maybe he will want
to supplement them with eternity bands later on.

Rick Hamilton
Richard D. Hamilton

Fabricated 14k, 18k, and platinum Jewelry
wax carving, modelmaking, jewelry photography

http://www.rick-hamilton.com
@rick_hamilton

Ryan,

This is not that big of a deal. The design with platinum and
yellow gold is very possible. The cost is more of the factor.
This could also be done in white and yellow gold too. All you
need to do is find a craftman to do this. good luck Nick

Ryan there is something really simple you are overlooking. after
the platinum ring is made and polished but before the stones are
set cut two wax blanks the ring size you will need and the shape.
cut them a little larger in width than is necessary. now heat the
plat piece andplace it quickly on you ring mandrel and just as
quickly slide the wax blank for one side up against it until it
makes a goo impression. trim away the excess wax that has melted
and you have an impression of the engagement ring and a perfect
fit. now doe the second ring on the other side. I always mark the
engagement ring in the shank with a very light scratch side a and
side b and also an arrow. then i mark the wax the same to they
can be alligned after casting. now clean up the plat. set the
stones and deliver. send the waxes off to be cast and when they
come back solder them to the plat. after cleaning and polishing.
this way you can deliver the plat. and save the wedding bands for
later application. wax does not to my knowledge deteriorate.
solder together with gold solder. luck

Frank

     Now, the problem is he wants to give the platinum ring as
the engagement ring, set the majority of the stones in it, then
before the wedding covert the ring to the above rough design. 

Usually when I make this type of ring its all assembled when
delivered. The problem is the center section is much larger than
the actual finger size when you make these (usually). Say if you
are making a 7mm band with a 4mm center platinum section and
1.5mm of yellow gold on each side (actually the yellow goes all
the way under), size 7, this is how I would do it. Carve a 7mm
wide band, maybe 1.5mm thick, mark 1.5mm in from each edge all
the way around, it should be about a size 6-6.5. Cut a shallow
(.75mm), 4mm wide slot up to the marks (your yellow section is
now basically finished). Next you start on the platinum section,
measure the outside diameter of the 1.5mm rails on the wax, this
will give you the size you need to make your platinum section
(probably a size 10 or so). Next you fabricate or carve your 4mm
wide platinum section to the size you measured and to the
thickness that will give you your desired rise (maybe only 1mm
thick). Once these two peices are completed comes the assembly.

You take your finished yellow section (remember its a size
6-6.5) and shrink one side just slightly. Then coat it with a
little grease. You now need to compress the platinum band over
the yellow band. A good way to do that is to find the hole in
your ring shrinker that is too small for the platinum band but
too big for the yellow band. Put the platinum band around the
edge of the hole, lay the slightly shrunken side of the yellow
band in the hole of the platinum band and compress untill the
platinum band snaps into place in the center of the yellow band.
Then stretch the assembled band up to the size required, this
will tighten the platinum band in place without solder. Of course
you need to finish the rails as you want them and ploish the
platinum first…etc.

This is not the ring you want but illustrates the problem you
will have.

I have made pierced bands with a different color metal insert
just under the surface, that might work. You could make the
platinum band, incorperating a cut out pattern all the way
around. And then when you were to join the yellow gold band to it
you could size up the platinum band just enough to slip over a
yellow gold sleeve, tack in place and done. I like this idea,
one problem is that neither the platinum or the yellow bands
could be too thick because together they might be too thick. Hope
this helps

Mark P.

Hello Ryan

This is a perfect ring for a bi-metal casting. Make the Platinum
section and polish it completely, just as you want the finished
ring to be. Along the outside edge of each side of the Pt ring,
drill small holes all the way around and ream them pear shape on
the inside with a ball bur. The hole has now a smaller opening
and a larger inside area, similar to flush setting set-up. These
will be your mechanical locks to the gold. Fill these holes with
wax and then attach the wax portions of, what is going to be the
gold ring, to the platinum. If you first wax a thin layer of
sticky wax all around the Pt, the carved wax will connect flush.
As the wax little wax filled holes attach to the sticky
wax/carved wax combination, it is “buttoned” to the Platinum.
Now clean off any excess wax from the Platinum assembly and cast
with a regular investment method. The heat will not harm the
Platinum and the metal, if cast at a little higher casting
temperature as usual, will make both a mechanical bond (buttons)
and a metallurgical bond as it interfaces with the Platinum.
Since the Platinum is already polished, finishing is a minor
additional task.Good luck and have a platinum day. For any help
with Platinum questions, please call me.(714)760-8279 9-5 0r 24
hrs at (714)760-8882 PLATINUM GUILD INTERNATIONAL USA Jurgen J.
Maerz, Manager of Technical Education, JA Certified Master
Jeweler