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Platinum alloy for hand fabrication


#1

Which platinum alloy should I use for hand fabrication of wedding
bands andother jewelry pieces? There is so many differen alloy
compositions available and the more I read about them the more
confused I am.

I am thinking about 90Pt-Ir, 95Pt-Ir, 95Pt-Ru, 95Pt-Cu, 95Pt-Ag and
other if you can suggest something.

On paper Pt-Ru and Pt-Cu have the best hardness after cold working.
I have heard Pt-Ir is also quite hard but Ru and Cu is harder.
Cobalt if mainly for casting but ih can reach really high hardness
levels after cold working. Pd, Ag alloys looks “soft”. I know there
are many many alloy compositions eg with gold, rhodium etc. But I am
looking to get one wchich will be reallygood for hand fabrication. I
want it to be good for the customer - so i will not bend or scrach
quickly. Albo would like it to be torch-weldable and it should not
oxidise.

Looking for your advise on this matter.


#2
Which platinum alloy should I use for hand fabrication of wedding
bands andother jewelry pieces? 

While other alloys have various properties that may be good, overall
10 percent iridium is the most traditionally used for hand
fabrication, for it’s overall combination of hardness, weldability,
and more. Ruthenium is sometimes used, primarily because it’s a
little cheaper, and may cast better.

The one class of alloys worth looking at which you don’t mention,
though, are the platinum alloys that can be heat treated. These can
be fabricated like the others, though sometimes not as easily.
However, after fabrication, they can be heat treated to higher levels
of hardness than normally possible, and if you’re looking for higher
strength and rigidity, these alloys deserve your attention.

They are proprietary, so ingredients aren’t so easily listed.
Discuss this with your metals supplier. As to the alloy being prone
to scratching, well, don’t expect miracles. Any platinum alloy will
be prone to scratches, even the heat treatable ones, though those to
a lesser degree. You should use platinum simply with the expectation
that this will occur over time.


#3

use 10% iridium. You can weld it, it does not oxidise and is a good
metal to work with. Have fun. Tom


#4

I prefer 95Pt-Ir. for fabrication. I like the color and how it
works. Second choice would be Pt-Ru. In order to stick to
international purity standards I only use 95% Pt. alloys. Each alloy
has it’s benefits and drawbacks but after many years of Pt.
fabrication that’s my choice. Other people may have different
preferences.

Richard Paille


#5

I would suggest the 95Pt-Ru, it’s a very good all-around alloy. It
willstay bright during melt or braze operations, can be easily fused
and is very ductile and is readily available. Its hardness will be
slightly better than 90Pt-Ir.

There are some 95Pt alloys out there that are harder than the
typical Ptalloys but have not become popular for multiple reasons,
Pt-In-Ga is one. It can be heat treated to reach hardness above
300HV, this is comparable tothe hardness of a cold worked 14kt
nickel white gold alloy.

Andy “The Tool Guy” Kroungold
Director Tool Sales & Stuller Bench
Stuller Inc.


#6

Tim and I are old school platinum fabricators. We learned our skills
from old european guys who learned their skills before WWII.

In traditional plat fabrication we use 10% Iridium Platinum. We melt
an ingot and then forge it down by half on all sides. Anneal and then
start rolling and drawing your stock and wire. I feel that 10%
Iridium plat is too soft for castings. For that I prefer Ruthinium
Plat. I don’t like Cobalt plat mostly because a non ferrous metal
that attracts magnets freaks me out. It oddly feels lighter weight to
me as well. I like the heft of plat.

Have fun and make lots of jewelry.
Jo Haemer
timothywgreen.com


#7

Thanks for replies.

I forgot to mention I need to make alloy my self since I could not
find ANYsupplier in my country. I can buy pure platinum and other
metals but no one is having alloys. But I preffer it this way. I
like to make my own alloysso I can change composition slightly to
fit my needs. I do it in gold so platinum will not be a problem.

Iridium is really pricey here - TWICE AS MUCH PER GRAM OF PLATINUM!
Its crazy. But since we are using 950 or 900 those additions are not
big so alloy cost will rise only a little.

Ruthenium is quite cheap on the other hand. But I am little affraid
about its safety. I know it has been used many many years and its
completely safe in everyday conditions. But from what I have read
Ruthenium releases Ruthenium Tetraoxide fumes when its heated above
800*C - and these fumes are really toxic. Does anoyone heard about
this? I couldnt find much about it - some international
suppliers mention about it, others dont. So I dont know what to
think.

I am thorn apart between 950PtRu, 950 PtCu, 900/950 PtIr.

Since it will be my first time making my own Platinum alloy I think
I will make one(probably Pt-Ir or Ru) and next time I will make it
different for trying. This way I will find which one will fit my
work preferences best. Ofcourse I have beed working with platinum
jewelry before but it was when I was working in UK - and we used
ready made stock for fabrication. But unfortunetly no one knew WHAT
ALLOY IS IT! Its rediculous for me :stuck_out_tongue:

Yes yes, I know I need all that equipment for Platinum,
contamination, safety etc.

I also understand there is no EPIC ALLOY that will be easy to work
and whenpiece is finished it will withstand everything and will be
forever in perfect condition. But I would like to pick one that will
be close to that :slight_smile: I mean, I always want to make things better then
the others. Many jerellersin my area doesnt give a shit about alloy
compositions - they just mix andmelt scrap :stuck_out_tongue: Other use poor colored
white gold etc etc.


#8

Hi,
My preference is 5% IP. I buy casting grain and go from there.
It does get harder when worked , an attribute I prefer as it makes detailing small parts less likely to deform.
On the other side, it anneals well. I prefer the slight resistance it offers when pave setting, a little more predictable (for me).
I torch weld as much as possible, I find it (5%IP) predictable. I use Map gas & oxy, micro torch. Just something I’m comfortable with.
I’ve worked closely with refiners since the mid 60’s & keep trying alloys as they become available, however, since iv’ve had pieces out there for so long I have to make sure colors and polishing techniques stay similar. As you work with platinum, things like hardness and color become more apparent, texture a well. Some materials draw well, others roll better. Some, though easy to set, wear poorly after 20 or 30 years.
Broad topic, lots of opinions… nothing NOTHING… beats experience, keep playing.
Thanks, Jim


#9

It’s J.Grahl Design
Thanks.


#10

I agree with your opinion Jim but like to add that one need to know how to play and then play safe.
Playing is more then just “alloying” some materials and see how it turns out.

Nothing beats experience and the bad ones are the ones we need to think about first and the most to learn from.


#11

Hi,
I completely agree about both “Playing” and being safe.
There are several things endemic to platinum that will bite you.
First is light shielding, I can’t stress enough to use proper shielding. “Floaters”, the small dark areas that are indicators of permeant eye damage. I’ve got them… not fun.
The second,
Always let the material cool sufficiently before viewing with out shielding.
Platinum burns are not fun, the material cools quickly giving the illusion (by metal color)it’s ready to be handled… beware… hot hurts…
This may not be of great value to those who laser only, I’m a torch fan (still), It’s just what I’m comfortable with.
The other expensive lesson is contamination.
Use clean files, avoid contact with steel or iron, They will actually blend with the platinum… then promptly embrittle it immediately turning it to scrap…
More later,
Best,
Jim


#12

Yes indead Jim, you hit the right button called contamination.
Add carbon to it in any form (acetyleengas, carbon sticks, charcoal blocks etc…).
Silica crucibles and investment containing silica are a no go aswell.

The best way -in my opinion- to work with platinum is having a workbench only dedicated for platinum purpose.

Pedro


#13

I hate the plat/cobalt alloys. Although very hard, I’ve had a few prongs crack, it’s a real bear to engrave, and it oxidizes when soldering. A lot of design houses are going this route as well as companies like Stuller. I always buy my platinum as sheet and do not do my own casting. My first choice is Pl/Ir, followed by Plat/Ru. One other negative about the cobalt alloy, You cannot weld it, The highest temperature solder you can use is 1600C with a lot of caution. Sizing is damn near impossible to do seamlesly.


#14

I could not agree more. tom