Many years ago, there were very few gold solders, nothing like the huge range of flows available today. In the past, many jewelers had to resort to using very low karat gold content. Have you ever been forced to use very low karat gold solder in a repair? You will notice the color problems, to say nothing of tarnishing over time or brittleness. In gold solders we see the gold content as high as 19kt or about 79% gold, leaving 21% (about one fifth!) available for alloys to adjust properties. To a large degree the more alloy percentage you have to work with the more you can change the properties of a metal. That is an important point. Platinum jewelry is 90% to 95% Platinum. That is the equivalent of about 21kt at 90% Pt and 23kt for 95% Pt! Gold solders still top out at about 80% gold. Above that figure we see only welding products.
Our trade needs Platinum solder that matches the Platinum content of the jewelry. Our trade is well accustomed to both "repair" and "plumb" grade gold solders. In what we call "repair solder," or "regular solder," gold solders are marked with their intended use karat. If it is stamped 14ye it is a lower karat intended to be used on 14kt. If it is stamped 14kye it is "plumb" solder. So, many jewelers readily accept the lesser gold content and enjoy a lower flow temperature, and lower cost for the solders.
In "plumb" solders, they are marked with the actual karat content, as well as flow and color. The lowest gold percent we see used in "14 repair" solder is at least 25% and usually much higher like 41.66%. Of course, with low gold content in solders, repair quality becomes an issue. The lower the gold content the bigger the quality issue. As we know 58.5% is the amount for plumb gold, so the solder matches the content of the jewelry. Very few jewelers are actually aware of the Platinum content in most Platinum solders.
With Platinum solders the situation is even worse than gold. In fact, many conventional Platinum solders contain no Platinum at all. Which explains why solders act so oddly compared to Platinum. Again the quality issue will raise its head! For quality purposes, precious metal solders should closely match the precious metal content in any jewelry.
WHAT IS WRONG WITH CONVENTIONAL PLATINUM SOLDERS
To get the flow temperature down the obvious trick is to reduce the Platinum, and replace it with other white metals that melt at a lower temperature. Those of us in the jewelry
solder trade use varying substitute metals for flow and or color. Many jewelers tell me of how they learned to weld rather than solder Platinum due to quality concerns. I admire the attitude but some jobs just cannot be welded. Besides,
ease of use is a great thing to have in any product.
The following list describes some typical ingredients in "conventional" or "repair" grade Platinum solders.
Nickel - We usually work to keep nickel out of jewelry where it is practical to do so. Europe prefers nearly no nickel at all in jewelry, with tough standards that are strictly enforced.
Silver - This is hardly a metal commonly associated with Platinum jewelry, but it provides important properties to conventional Platinum solders.
Palladium - Too high a melt temperature to help much at all, but it is the very common element found in higher temperature solders. This metal does swing quite a bit in price, complicating the pricing equation from time to time. Oddly enough, palladium has been more costly than any other element used.
Gold - A good metal to use with Platinum in solders, but the percentage must remain low. The obvious color problem would come up above a certain fraction of the mix.
Cadmium is not suited for Platinum use for a variety of reasons, including exposure risks.
These metals do cause problems. Poor color, porosity and some very visible seams. This is often fixed with rhodium plating, but that is another unneeded expense, and it will wear off with time, which can disappoint the customer. Due to the unique nature of Platinum, we always had to compromise the Platinum content of the solders.
Solder manufacturers do not ordinarily disclose the complete elemental content in their product. When asked, all reputable solder makers will readily disclose precious metal content. The rest is rightly considered to be proprietary, within the bounds of MSDS publication requirements. When you next use any solder, ask your supplier to inform you how much precious metal content is in there. The lowest Pt % we see in Platinum Solders is 0%, unheard of in gold, and rightly so.
14kt Gold is easy to adjust for temperature, after all we have 41%+ of alloy to work with! Here in Platinum we have the noble white metal, assembled or repaired with a solder that has little to no common elements with the jewelry we are working on. This was always necessary because of the temperatures and elemental properties involved. Only the new plumb Platinum solders material have much Platinum in them at all.
THE NEW PLUMB PLATINUM SOLDER
This situation now comes to a close. Our "real world" tests show the new solder is applicable for any job where the indicated temperature is appropriate, 1300°C to 1500°C. Sizing, assembly and many
repairs can be done with the new solder. Even Platinum findings and settings can be assembled with this stuff! From now on you all have the option of your Platinum solder containing 90% Platinum or more to match your Platinum jewelry
casting or fabricating alloys.
You can stop thinking about using solders perilously close to the flow temperature of the jewelry. The new plumb Platinum solders flow at 1500°C or lower.
PAST EXPERIENCE IS APPLIED FOR SUCCESS
PM/West has always searched for alternative flow enhancing elements.
"Cadmium Free" is a primary requirement in all our formulas for solders or anything else. As a result, our experience with very low flow elements is more extensive than many other firms, putting us in an unique position to develop this product. Other innovators could use our method to develop other new Platinum products.
Our ability to create and test small amounts has made it possible to try many ideas. Lower expense equates to more effort to benefit from.
DIFFICULTIES WE OVERCAME
At first we made a bar or ingot of this solder, but it was so brittle, it was beyond rolling and annealing. Also we tried a small pour to begin with. New product development is not for the timid or the
impatient.
We spent a lot of time with trial and error. A lot of metal got ruined, then refined and reformulated before we had a working solder. Thank goodness we are a refiner! Experience tells us that persistence is a required skill. For those in charge of a company, I suggest you be patient with your people.
WHAT WE FOUND TO WORK BEST
Materials "X" "Y" and "Z".
"Secret" ingredients for now. We are using materials that have proven themselves in other applications. While we pass through patent issues, (the preliminary work is
all in) we are not yet divulging the elements involved in these new solders. Please remember that this is a very new solder, and be patient with our R&D.
A consistent "solder" alloy. After much trial and error, we were able to develop an alloy that allowed us to vary the Platinum percent, to vary the flow to achieve 3 flows of solder Easy, Medium, and Hard. This is an old trick we learned while making lower karat gold solders. Lower the precious metals content and you lower the melt temperature. Ironic that a low karat gold solder trick would point the way to a high karat Platinum solder!
Vary the Platinum percent to vary the flow temp
90%Pt is "Easy" 1300
92.5%Pt is "Medium" 1400
95%Pt is "Hard" 1500
What this means is that you can step assemble with this solder. It also means that you can use the 90% solder on
the newest 95% Pt heat treatable casting grains from Hoover or Imperial or anyone else. An important note- PM/West is NOT in the production of any "heat treatable" Platinum alloys.
INITIAL PERFORMANCE REPORTS FROM THE FIELD.
No reports of dark color or other color problems in 95% Pt jewelry
- No problems with "polishing out" at all. This solder approximates the hardness of most common alloys.
- May be too white for 90/10
- Some minor "ridging" is reported. In certain circumstances the solder can harden up, but is easily fixed with conventional sanding and polishing.
- Wire form may be made available at a later date. This solder works just fine on all conventional Platinums and on cobalt Platinum alloys. Retipping is NOT recommended, as 1300°C is still too hot.
Like all PM/West products, this solder is cadmium free. Our experience with alternatives teaches us to be careful regardless of the ingredients used. But, many solders do include cadmium, with its well documented hazards.
What the Future Holds for Us
- More available flows. Push the Platinum percent lower to get below 1200 for Cobalt Platinums and oven assembly
- Increase Platinum percent for special extra hard applications
We are the first manufacturer to develop "Plumb Platinum" solders. We have trademarked the name and are pursuing our options under patent law. The state of the art advanced today, through our combined efforts with others who speak at the Guilds' invitation. Thank you all for listening and taking the time to advance your own skills.
It is exciting to be involved with an advance like this, and in the coming years I hope to see the need to use non Platinum solders on Platinum jewelry diminish to nothing. I encourage all of you to push the limit in Platinum and gold
product development.
New alloys, new investments, new solders, and new marketing methods have come together in just the last year or so! Opportunities abound for the daring. By daring I mean innovators who are in for the long haul. Dare to research, then produce and market your product. The bottom line to my paper is really just to glean all you can from all the available trade sources, use your own strengths in your sense of direction...
Then persevere. Patience pays.
V7N2
Developing Plumb Platinum Solders
Daniel Ballard
Precious Metals West
This is an abbreviated version of the original work. For full technical details, please consult the original paper.
