Platinum Sterling Binary Alloy?

Hello everyone,

I am on a quest to find the perfect the sterling silver alloy, I have grown frustrated with the never ending combinations of silver with unknown ingredients that reduce tarnish and firescale while somehow being deficient in some other way. The best ones seem to be either platinum or palladium sterling silvers.

To avoid all the frustration, what if I just cooked up a binary sterling silver with a really hot torch but rather using copper, I used platinum. Would this be hard enough? Is there something I am missing here as to why a silver-platinum binary alloy has never been done? If not platinum, what about a silver-palladium binary alloy, that is 92.5% silver, 7.5% palladium. Would that be hard enough and just be an all around improvement?

I calculated the cost, $5.13 Canadian per gram or $159.55 per ounce. If you use platinum’s historical highest ever cost it works out to $9.25 a gram or $287.68 an ounce. Certainly more than regular sterling, however I feel this will only serve to increase its cache and equalize sterling silver amongst the more noble gold.

What problems, if any, are there with a sterling silver alloyed with all platinum or all palladium, no firescale, presumably harder, less tarnish, high temp. Enamels, greater perceived AND real value, doesn’t even turn black when you heat it, and at most ten bucks a gram. What’s there not to like?

Interested in hearing your thoughts,

ArgentumMoon

1 Like

Janet in Jerusalem

Once again, thank you :slight_smile:

There is a platinum silver alloy. It is 92.5 silver and .05 platinum and the rest are something else. The company that makes it sold the rights to use the name and it can be seen on the jewelry shopping channels on the television. I don’t want to post the name as it is a trademark violation and I don’t need more legal issues. The cost is like $200 an ounces vs $30-40 for AS depending when you bought that. I call it silver +P and if you are a firearms enthusiast you’ll understand the +P! The color is beautiful and looks great with 14k. But the price is just so much higher…

1 Like

Wow! $200.00 an oz?! Continuum is alloyed with palladium which costs more than gold or platinum and it’s only $44.69 and oz today.
-Jo Haemer

Only $44.67? I would have thought Continuum would be more. If it’s got around 3% palladium and palladium is $1365 an ounce, then wouldn’t just the palladium be around $41 for an ounce of Continuum?

I’m a huge fan of Stuller’s Continuum. When I was hanging out with a bunch of smarty pants PHD metallurgists at the Santa Fe Symposium we were discussing silver alloys. The general consensus is that Continuum is the closest thing there is to a perfect silver alloy.
It doesn’t get the PR that Argentium gets but it is in my humble opinion far superior. When working with silver it’s just about the only alloy I use. It’s only a few bucks more than AS and worth every penny. Stuller has a fact sheet online but it’s written from a metallurgist’s point of view by guys with fancy kilns, argon gas, vacuum atmosphere casting machines, precise thermostats, etc. If you want advice on how to work this stuff with a torch and basic tools from a bench monkey’s perspective feel free to PM me.
Jo

3 Likes

Correction 6.5% platinum; 925% silver and 1/2% of alloy. Sorry

Wow, very interesting, if anybody has experience about Continuum for ENAMELING I would love to hear!

Hi Jo!

A couple of questions:

  1. How does Continuum compare to Sterlium, in your experience?
  2. Do either of these two metals have the slumping problem of Argentium? Shortness?
  3. Does your favorite, Continuum, have any disadvantages relative to the other two?

Thanks!

Janet in Jerusalem

I considered argentium but was told argentium tarnishes a yellow colour, I am guessing this is copper sulphide somehow? I won’t use argentium if it indeed tarnishes faster than regular sterling to a yellow colour. What about sterlium? Isn’t that Stuller’s silver-germanium alloy?

It enamels beautifully.
Jo

I was wrong. The price was listed for 10 dwts rather than one oz.
I always order metals one oz or more at a time.
That said it’s still much cheaper than gold and is much easier to work with for fabricating than Argentium. Argentium requires separate crucibles and polishing buffs as contamination wth other alloys is an issue. It also requires 50% fresh metal added after it’s been cast or melted for an ingot. Neither one is an issue wth Continuum. I have some that I have melted and reused a dozen times with no issues at all. It is also much more stable at soldering temps than Argentium. Also Argentium as cast is only 70 vickers. Continuum is 97-117 as cast. After hardening it’s 158 vickers. As hard as cast white gold. Annealed it’s as soft as sterling in the same state. It has great tensile strength and is perfect for stone settings. It wears very well after hardening.
I use it for eyeglasses as it is lighter than gold or platinum and is very strong and almost impossible to bend after hardening so it stands up beautifully for every day wear.
-Jo

2 Likes

So, in essence, the perfect silver alloy? Doesn’t firescale, less tarnish and not too soft? Sounds lovely. I really ought to perchase an ounce some time…

I’ve never used Sterlium. Cont. is very stable at high temps. It does tarnish faster than Argentium but not nearly as fast as sterling.

1 Like

Finally I am discovering someone writing about this silver alloy, Continuum. I have worked mainly with karat golds for decades but with sales of the yellow metal in the tank, have decided to try this alloy for a few projects. I was mainly wondering about basic workability like torch casting. I am old school centrifugal machine guy and do almost everything by feel … Yes many burned fingers … Oh they heal. :slight_smile: Recently bought 5 oz of Continuum and am about to try using the stuff. Even Stuller seems a bit short on actual procedures but I am waiting to hear back from their tech guys on using my acetylene torch to melt and cast… plus flux type? Thanks for sharing what you have and any other tips would be greatly appreciated. Cheers from Canada … LuckyT

Hi Jo … My gosh would I ever appreciate any info you might have for me with regards to using Continuum … I’m from Canada and given the current price of Palladium this alloy is pricy, especially with our weak currency. Many Thanks in advance and all the best from up North on Vancouver Island
Cheers, Terry Venables

Terry- I’m happy to help. I really should get my act together and just write a paper on Continuum and how to use it from a Bench Monkey’s perspective.
I have cast and fabricated with it. Cast like you usually do, but the flask should be a little hotter than usual. We vacuum cast but centrifugal should work just fine. Use your usual burnout sequence. I usually cast when the flask has been held at 900-1000 F for about an hour after full burn out. With Continuum I cast at 1100-1200 F. Cont. has a higher melting and liquidus temp than sterling. It takes a good while to get there so I always make sure I pee before I start:-) My test for the right temp is that when I jiggle the crucible the metal splashes around more like water than honey. I use just good old fashioned borax for a flux. Avoid using a carbon stirring rod. I use natural gas and oxygen. I have no idea if acetylene is good or bad for it. Call Stuller and ask to talk to John Butler or Shan Aithal. They will be happy to talk to you. After casting wait for the glow of the button to dim and then quench. 800 F is the ideal quenching temp for maximum hardness. If you don’t get it right that’s fine. You can later kiln harden it.
Continuum solders more like gold that silver. You do not need to heat the entire piece up as much as you would if it were silver. Just get it warm and then you can go in and almost spot solder like with gold. This makes it easy to solder joins near each other without having to go to lower temp solders. Great for soldering on prongs. I use paste flux for soldering. It fuses nicely. I usually fuse my first seam or two when fabricating heavier pieces together. When annealing the metal let it cool a bit. It doesn’t need to be totally cold, but If you quench at 800 it will be harder. I have found that sometimes I get lucky when soldering on ear posts and quench while it’s still hot and the posts come out nice and stiff. It’s ideal for earring posts especially for folks who have allergies to copper in sterling. However if I don’t get it right I just later kiln harden the whole piece before setting stones. To kiln harden I put the piece in an 800F kiln for 30-40 minutes and then immediately quench. You can air cool and it is still harder than sterling but not as hard as a quick quench. I use IT solder or any good high temp eutectic or enameling solder. The lowest temp I use is hard silver solder. Pour yourself an ingot and make some wire, bar stock and sheet to experiment at first. Don’t worry about reusing the metal. I have remelted cont as many as 10 times with no issues at all. You can build much lighter weight pieces that won’t distort or bend. I’ll attach an image of my last piece that was done with reused cont. When setting stones with bezels, prongs or bead setting it behaves more like fabricated platinum and wears like it as well. My husband swears that he can raise beads like a fence post with out the drag and burr wearing like platinum. It is also perfect for making clasps that need to have some spring. We made a large bracelet out of sterling to save on cost, but used Cont. for the clasp. Sometimes I use it for stone settings on a silver piece for the sake of durability.
It polishes nicely. I like Picasso blue for the last buffing. It oxydizes to a lovely black with liver of sulfur. I use a good wax after rinsing and drying to complete the darkening. It enamels like a dream. It does tarnish faster than Argentium but slower than sterling. I will sometimes plate a finished piece with .999 silver to delay the tarnishing or just wax it with a good floor paste wax or a good car wax. I use Renaissance wax on earrings or pendants Especially if they have blackened areas that I want to really pop.
So just take some of it and abuse it to see how it works until you get comfortable.

7 Likes

thank you Jo! I just hadn’t come across anything details about Continuum. I have been using Argentium, for fusing and because I like its soldering properties. BUT it likes to go an ugly gray. Does Continuum avoid that habit?

jmdw in Asheville, NC

WOW… This is an extraordinary treatise on Continuum! Thank you ever so much! You are most kind to write this and I appreciate more than you can know! Had a look at your website and your art is amazing. Thank YOU Thank YOU … TerryV