I am casting a ring of platinum and need to fuse gold into some
recesses in it. I would like to use high karat or fine gold, to
get the most contrast between metal colors.
Has anyone done this successfully, and how?
What karat seems to work best?
I am also interested if anyone has achieved the "crystalized"
gold look that is appearing in German work. How is this done?
Thanks,
Stephen Bargsten
I’ve fused high karat golds to platinum. I’ve always treated it
like solder. Easy to do. Any karat or color.
I’ve gotten the crystalized look in the past by casting those
portions and electrostripping with cyanide based stripping salts.
Strip slowly and hot. Rolled metals won’t show the same
structure.
Bruce D. Holmgrain
e-mail: @Bruce_Holmgrain
http:\www.knight-hub.com\manmtndense\bhh3.htm
snail mail: pob 7972, McLean, VA 22106-7972
phone:: 703-593-4652
Stephen what you would like to do here is called Kuem bo. I
believe there may be a paper on this technique here at this site,
but am not sure. It is definitely available through the Brain
Press. I learned the technique from Charles Lewton Brain (Brain
Press) at a seminar. Basically, Platinum is a perfect medium for
this application. Have both pieces perfectly clean, roll your
24k to next to foil thinness (past foil for other metals beside
platinum), heat the platinum until your 24k piece sinks into it.
This is simplistically stated, but the basic idea. Hopefully
Charles will weigh in on this one. Hope I helped, Mike
Stephen what you would like to do here is called Kuem bo. I
believe there may be a paper on this technique here at this site,
but am not sure. It is definitely available through the Brain
Press. I learned the technique from Charles Lewton Brain (Brain
Press) at a seminar.
Hi Stephen, Mike,
Mike you are right, keum-boo (and yes there are full details on
the Ganoksin Tips page) keum-boo works very well on palladium and
platinum and offers enormous design options. But I think that
Stephen is refering to a method in use in the US by Steven
Kretchmer and in Europe by a number of companies where gold is
inlaid (read either cast or fused with heat into depressions in
the platinum object) and then heat treated so as to enlarge the
grain sturcture (probably by heating for a long time at a high
temperature or if cast in then a very very slow cooling), then
etch in some manner (see Bruce’s email on how he obtains this
surface). The surface has these beautiful crystaline growth
structures which contrast with the smooth high polished platinum
surface. The crystaline surface resembles what you see on
galvanized zinc objects (only gold of course). It is quite
beautiful and mysterious looking. Charles
Brain Press
Box 1624, Ste M, Calgary, Alberta, T2P 2L7, Canada
Tel: 403-263-3955 Fax: 403-283-9053 Email: @Charles_Lewton-Brain
Metals info download web site: Learning Center - Ganoksin Jewelry Making Community
Product descriptions: http://www.ganoksin.com/kosana/brain/brain.htm
Links list hosted at the Metal Web News:
http://tbr.state.tn.us/~wgray/jewelry/jewelry-link.html
I’ve been thinking about fusing gold to platinum, also inlaying
22k in some of the niobium pieces that I make.
Richard D. Hamilton
Fabricated 14k, 18k, and platinum Jewelry
wax carving, modelmaking, jewelry photography
I am also interested if anyone has achieved the “crystalized”
gold look that is appearing in German work. How is this done?
Hi Stephen, This look is achieved by a kind of grain etching
similar to what the labs of steel producers do to show the
cristalline structure. In precious metals it is done with the
following solutions: for fine gold: 20 ml nitric acid, 60 ml
hydrochloric acid (this is aqua regia), used hot and always as a
new solution, as it disintegrates for 18k yellow gold: 100 ml
destilled water, 5 g potassium cyanide, to this add just before
use 5 g (NH4)2S2O8 (sorry, don’t know the English word, probably
persulfate of ammonia?) mixed with 100 ml destilled water, 30
sec to 2 min for yellow gold: 100 ml dest. water, 100 ml hydrogen
peroxide (3%), 32 g ferric chloride Hope you can use something,
Markus
Hi Stephen, Puddeling high purity gold into recess platinum is
not all that difficult. Be sure your metal is clean and you plan
your steps. You can use a rod of gold and feed it into the spaces
as you heat the platinum from below, or cut small snips and fill
the cavity and then melt it. Just be careful and control your
torch. You can bring out the crystal structure of gold with a
mixture of chromium trioxide, hydrochloric acid and nitric acid.
The surface of the gold is swabbed gently with this mixture for
6-10 seconds. The result will ( should) be a matte finish with
the rich gold color and structure of the metal. The higher the
purity , the prettier the color and structure. Acids are
dangerous. Good ventilation is required. Have a baking soda
solution for neutralization at hand and be very careful. A
stripping solution will do a similar but not as good a job. Hope
that helps. PLATINUM GUILD INTERNATIONAL USA Jurgen J. Maerz, Mgr
of Tech. Education
Dear Markus, Charles, Dave, and all,
Thanks for the info. It looks like the easiest etching mix
would be forfine gold, Nitric and hydroclhloric.
I have a couple more questions:
How hot should the solution be?
I was thinking about casting the fine gold into recesses in the
platinum, a sort of cast inlay. I have never cast fine gold, and
I am wondering if it freezes/solidifies instantly before it could
flow into the flask and the platinum… Does it stay liquid long
enough to cast, or should I use 22K?
It sounds like (per Charles) the gold needs to stay hot for an
extended period to form a large crystal structure. I was
thinking about casting the flask, and then putting it immediately
back in the oven instead of quenching it. It would gradually
cool from about 1000F to room temp in 1-2 hours.
Do you think a high polish surface on the gold would be the best
surface to start with?
I will definately do a test run on this will a small piece of
platinum first! Too big $$ to mess up!
Stephen Bargsten
In a message dated 97-05-23 22:42:57 EDT, you write:
following solutions: for fine gold: 20 ml nitric acid, 60 ml
hydrochloric acid (this is aqua regia), used hot and always as a
new solution, as it disintegrates for 18k yellow gold: 100 ml
destilled water, 5 g potassium cyanide, to this add just before
use
Markus, Stephen, Isnt a cyanide and acid mixture used in gas
chambers to kill people? I would never think of mixing the two.
Years ago, I did some bombing with cyanide and 30% hydrogen
peroxide and it scared the %@$! outa me…Just a thought Ken
It looks like the easiest etching mix would be forfine
gold, Nitric and hydroclhloric.
I have a couple more questions:
How hot should the solution be?
Hi Stephen, The book says “hot to boiling”. Be very careful when
pouring the nitric into the hydrochloric acid, it will get very
hot, could even start to boil and spit at you. Best is to put
the vessel with HCl into a lrger one filled with cold water as a
coolant, and to pour the nitric acid very slowly and in a thin
stream, just beyond dripping. Stir constantly, but slowly. I
used a mixture of nitric and sulphuric acid to get a shine on
brass castings, just by dipping them into the solution for 2
secs, worked great. Markus
Markus, Stephen, Isnt a cyanide and acid mixture used in gas
chambers to kill people? I would never think of mixing the two.
Years ago, I did some bombing with cyanide and 30% hydrogen
peroxide and it scared the %@$! outa me…Just a thought Ken
Hi Ken,
You are right, any acid added to a cyanide solution creates
gases of prussic acid, lethal at 0.1 milligramm per kilogramm
bodyweight. But I did give 3 different recipes, the one with
aqua regia for fine gold, one with cyanide for 18k yellow gold
without any acid, and one with hydrogen peroxide and ferric
chloride for yellow gold. I’d never, never propose to add acid
to cyanide! Markus
hi ken, i think marcus just forgot to put a period after
’disintegrates’ . this had me thinking the same as you. geo fox