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Platinum &18k sizing techinques


#1

looking for info on sizing platinum with 18k inserts , tips
techinques or recommended literature. I have experience with
platinum. Would appreciate any help in this area.


#2

looking for info on sizing platinum with 18k inserts , tips
techinques or recommended literature. I have experience with
platinum. Would appreciate any help in this area.

I just finished a pair of wedding bands that involved casting
18k yellow gold around fabricated 10% iridium platinum inserts.
Several people on the forum offered advise- polish the platinum
inserts, add wires or other extensions to fix the insert in place
in the investment while the burnout and casting takes place, in
general you need to cast the piece carefully. The second casting
should be the lower temperature alloy.

J A Henkel, who just started posting, has experience with this
process. You may want to contact him.

Rick
Richard D. Hamilton

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

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


#3
looking for info on sizing platinum with 18k inserts  ,  tips
techinques or recommended literature.  I have experience with
platinum.  Would appreciate any help in this area.

Hi John: Whenever you are working with a bi-metal piece, the
lowest melting point metal determines the technique. So if there
is 18K next to Platinum, Gold technique must be used. The higher
temperature of the Platinum filler metal would melt and destroy
your ring. Solder the shank with 18K or 20K white solder, then
burnish the seam with a tungsten burnisher, till you have made it
invisible. Platinum’s surface will allow you to almost "smear"
the Platinum to cover the seam. Now sand paper and polish the
ring as you normally would…

For additional about repairing Platinum, call Platinim Guild
International technical Hotline at (714) 760-8882.
Have a Platinum day
PLATINUM GUILD INTERNATIONAL
Jurgen J. Maerz
Manager of Technical Education, JA Certified Master Jeweler


#4

Thanks for the great info. This will be very helpful. We are
starting to see a lot of gold/platinum rings, mostly wedding
bands. This seems to be to popula r trend now. I wasn’t aware
you could burnish the platinum to cover the soldered joint. I’m
looking forward to trying this method. Thanks again.


#5

Something that I have been curious about is, why is it that
older platinum rings seem to crack at the solder seams when
sized. Even if you weld them, when you round them out they often
crack. But new platinum mountings that I make almost never crack.
The procedures are the same, but the results are so different. I
have tried all the various platinum solders, and the only way I
can assure no cracking is to make sure the old ring doesn’t need
to be rounded after sizing. I have wondered if the material
degrated in some way over the years, the alloys or the bonds. I
just don’t get it. Mark P.


#6

Some one wrote a tip about burnishing the solder joint befor
polishing, I avoided the area that had been soldered and
burnished. I polished the other areas with I belive it is a
diamond based compond. And it worked great!!

I have seen the problem with older Plat jewelry cracking. I
wonder if anealing the piece before working on it would help?

Rick


#7

Hi Mark and all Orchid subscribers.

Platinum alloys tend to crack when they are taking on carbon
through a reducing atmosphere. Sometimes soldering a ring on a
charcoal block can almost guarantee contamination, as during the
welding/ soldering process carbon enters the grain boundries of
the metal. This will lead to cracking once you place stress on
the ring. The same reducing situation can be created by using a
carbonizing flame , or welding the ring with an accethylene /
oxygen flame and not burning all the fuel. The carbon in the gas
will do the same. Oxidizing flames and a alumina soldering block
will solve most problems. Also the use of fire-coat and fluxes
should be avoided. They are not doing anything other than cause
contamination at high temperaturs. Be sure to think Platinum
when working Platinum. I hope that helps. For more technical
about working with Platinum, call me at (714)
760-8279 or leave a question at our Platinum Hot line
(714)760-8882

Have a platinum day
PLATINUM GUILD INTERNATIONAL
Jurgen J. Maerz, Man
Manager of Technical Education, JA Certified Master Jeweler


#8

Mark what you are experiencing is metal fatigue. It is actually
a molecular cyrstalization of the metal molecules. AS stresses
build up with wear the solder joints ,because of the alloys, tend
to crystalize first and are the weakest point. a good annealing
before repair and after a good soak in the lye pot should relieve
this problem in most situations unless ofcorse the plat was
contaminated during solder stage.

Frank


#9

hi mark, i like to cut out any sizing ‘slugs’ first and then weld
the seams.

i will roll out platinum sheet til my rollers are shut
completely and i have some very thin platinum. i then cut a
piece that is slightly bigger than the shank in cross section.
the platinum piece is inserted into the seam and the edges that
are left proud are melted into the shank. on not so thin shanks
the ‘pallion’ will fuse on all four sides, on thicker shanks
you’ll have to fuse it from the other side as well. hope i made
sense.

best regards,

geo fox


#10
 i will roll out platinum sheet til my rollers are shut
completely  

George, I will do the same thing, or use seamless plat solder
etc. I am having no trouble with the new platinum things we make.
But the older (30 years or so) seems to crack when rounded out
after soldering. I clean the peice (don’t want to burn any crud
on the dias, by the way the liquid plummer worked, thanks), I put
it in spring tweezers seam up, I put boric acid and alcohol on
the stones only, I put the solder in the seam or on the seam, I
use a tiny bit of flux because I can’t help myself, solder with
gates of hell temperatures, linger a little to insure the seam is
| fused all the way thru, let it air cool, throw in the
pickle for a couple of minutes, take out, file the inside of the
ring (no cracks), round it out, and may have a crack at the seam,
( now thats a long sentence). This only happens on the old ones.
I can avoid it by making sure its round first, to avoid the
rounding out after. I just don’t understand it. Do you? Mark P.


#11

hi mark,

i’m not sure i understand it, but here are a few observations
(and a question too). the flux as you know is not neccessary,
but is not causing our problem. what i think is causing the
problem is uneven temper in the shank. another jeweler told me
that platinum can become so work hardened that it can impress a
groove in the pins on a roller mill if not annealed (bummer).
combine this with the very poor heat conductivity of platinum we
might have the cause of the problem. you have an age or work
hardened shank that is brazed in the middle, since the shank
isn’t going to bend readily, the joint fails. the brazing
operation may not even anneal the shank around the joint because
it may not get hot for long enough. i would go with juergens
reccomendation of annealing the shank thouroughly, (one minute
per millimeter the texts say)then brazing. use an agressive heat
sink on those diamonds. (hey juergen, what would be a good heat
sink besides toilet paper and water for platinum? )

do you use the spring tweezers when you do the new rings as
well? if you use them in that case with no problem, it isn’t the
cause of the problem with the old rings. i used to hold sizing
joints shut with them and experienced alot of seam failure
(creates uneven tension). now i just hold pieces in place with
them.

mark, what is seamless platinum solder? is it pure platinum or
1700 c solder? do you think the gate of hell is really that hot?

best regards,

geo fox


#12

Mark… I understand it…that tiny little bit of flux, that
you use to “make sure it flows all the way through” is what
causes your problem. Flux has only one purpose: to keep the
firescale or other oxidation from interfering with the flow
of solder. Lets look at that…you aren’t using solder…there
is no oxidation…but there is flux…As you heat the metal to
the"gate of hell" temperatures as you call it, that flux
becomes a contaminate. Remember flux is designed to work at
temperatures between 1000F and 2000F, your welding
temperature is over 3200F, so what ever flux was there, has
done its job many degrees ago and is now entering the grain
boundaries of the Platinum and contaminating it. Thus, when
you bend or otherwise deform the metal , it simply will
crack.Now for Pt/Co there are some high temperature fluxes
available, but these are NOT Batterns “Self Pickling” or
"Handy- flux". these are available through welding supplies
and are called high temperature brazing fluxes. There are
several brands. So most likely you do NOT need flux at
all…it will hurt you more than help.

For additional help with Platinum questions please call the
PLATINUM GUILD INTERNATIONAL USA Hotline (714)760-8882 0r
direct (714)760-8279 Have a platinum day Jurgen J. Maerz,
Manager of Technical Education, JA Certified Master Jeweler

#13

re: Platinum sizing,

Hi, I just bought a plat. ring from stuller, they send a warning
sheet with it. It says to not use flux. I tryed it before I had
the warning on another ring a couple of weeks before and it broke
several times before I completed the job. When I didn’t use flux
everything went fine. So, no flux on Platinum. Fred


#14

George Fox, The seamless platinum solder is 1700c solder. I hope
I never find out if the gate of hell is really that hot, all I
know about the gate of hell is my mother-in law is somehow
involved. Jurgen thinks the flux is the problem, I will first try
eliminating the flux, and then try annealing, I am concerned
about burning the diamonds. I will error on the side of stone
saftey and that may make the annealling process a waste of time.
I do use the tweezers the same way on the new platinum peices, so
as you said that is not the problem. It is going to be hard to
give up my old friend Mr. Flux, but it sounds like it may be a
bad habit when working in plat. Mark P.


#15

I resized a platinum ring (up) today with 1600 and no flux, I
had to use gentle heat at first to keep the solder in place, but
the welds were pefect. Sure do like my Didymium glasses.

Rick
Richard D. Hamilton

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

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


#16

hi mark,

i think jurgen is the maven here, though we should still be
curious why fluxing would affect the older rings exclusively and
not the new rings.

i’ve never used flux on platinum before, because i actually did
something intelligent (for once); i took a class. they told me
not to use the flux and why (same reason of contamination that
juergen explained). but i’ve read in a not so recent book that
tells you to flux the work! so it was done by some one on a
regular basis with enough success (presumabley) to be written in
text. though i’m not going to start fluxing platinum.

i’m also still curious to know if there are any suitable heat
sinks that will not contaminate platinum besides toilet paper
and water… something like that delft clay. i’m afraid to try
it on platinum for fear of contamination. i’ll call jurgen
directly and let you know what he says.

best regards,

geo fox


#17

I resized a platinum ring (up) today with 1600 and no flux, I
had to use gentle heat at first to keep the solder in place, but
the welds were pefect. Sure do like my Didymium glasses.

Hiya Rick, You may tell me to go suck eggs as to how to advise
you to solder platinum. In all shanks or bands depending on your
own accent. I come from New Zealand not to far away from the
home town of John Burgess so as radical as ever with no solder at
hand i take a very small amount of the same metal that the ring
is made from. Sample from band is preferable. Flatten with bench
hammer observing carefully which way it has jumped out from under
your hammer and landing after circumnavigating your work studio.
Retrieve item and note where you have put it.!!!

File join square and with tension position small flat of metal
in join.

With your new found glasses or personally I will post my design
half glasses on the page one day in the future. Didymium glasses
are good however it is just what up get used to. Not that I would
not change if I was proved wrong. I am far from perfect.

Apply heat to join and just watch as the platinum pallion melt
into the band.

Conclusion: No solder mark and secondly no where after polishing
to you see “polish out” No need for solder which will weaken the
band. No flux nice and clean!! Lastly no hassles engraving sides
of band …

Epilog: Any correspondence welcome re sizing. John (Aurum) (may
the flux be with you but not when using platinum


#18

Personally having had small red hot sections land in my lap, I
prefer to take a more conservative approach especially on old
pieces such as the one I just sized. You are right about welding
with the same alloy, except it seems with the Stuller cobalt
alloy- but I had no color match or solder seam problems in this
case- just sanded the joint and polished with Zam. The didymium
glasses are a necessity- they fit under the optivisor and allow
me the ability to actually see what I’m welding.

Rick
Richard D. Hamilton

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

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


#19

… i take a very small amount of the same metal that the ring

is made from. Sample from band is preferable. Flatten with bench
hammer observing carefully which way it has jumped out from under
your hammer and landing after circumnavigating your work studio.
Retrieve item and note where you have put it.!!!..

I am suffering from chronic overload of the brain, so my memory
is failing me, but hopefull either Jurgen is out there somewhere,
since I am trying to remember what he told me back in JA NY, or
someone else can help. When should you use solder vs. welding
when working platinum? I seem to remember it having to do with
the alloy used for casting vs. fabrication materials, but I can’t
seem to remember when to do what.

Sharon


#20

Sharon,

I can. I don’t have alot of respect for platinum solder,
platinum is such a pure metal compared to all the others we get
to work with that I hate to use platinum solder which is a
comparativly low purity. If it cannot be welded cleanly then I
resort to platinum solder. One of the criteria for welding vs
solder would also be if there were solder seams, other metals or
stones nearby. If so, then I would use solder. My experience
thus far has been with 5-10% IridiumPlatinum. Some of the other
alloys could have other characteristics that I’m not aware of.

Good Luck
Ray