Working With Palladium White Gold
While nickel based white gold is commonly used and very well understood, palladium based white is gaining interest and sales. Some of us sell to the EU or Japan, and some of us have customers sensitive to or about nickel.
Palladium white gold alloys have some general characteristics. Aside from gold and palladium, copper and silver are usually contained in the alloy. Different alloy suppliers will reflect different conclusions as to the “best” ratio of these metals, and many have innovations that affect behavior. Many of these innovations are in trace elements, held here as confidential. The effect of trace elements on color is usually invisible or designed to push the color whiter.
In this instance we have assembled some of the older formulas useful as a general color guide. As you might expect the higher palladium content is reflected in a whiter or perhaps grayer tone. Ordinarily the palladium content is from five to twenty five percent of the 14kt. In 18kt we see about 12 percent most often. This is reflected in the color coordinates of the samples.
The profound benefit of palladium is its softness for fabrication, setting, or engraving. Another advantage is the evidence that few if any people show any allergy or sensitivity. I suggest 12% palladium in 18kt gold, and at least 8% in 14kt and at least 11% in 10kt. In 10 and 14kt more is better, but that brings us to the biggest problem with palladium.
The primary disadvantage of palladium is that it can add twenty to fifty dollars per ounce to the cost of casting grain. This varies by the amount of palladium used and the market. If for any reason palladium costs escalate dramatically, the added costs will increase proportionate to the market price, just like gold. Secondarily, some special handling during high temperature smelting or casting is often required and added refining costs can play a part.
To estimate the added costs of palladium per ounce simply multiply the London Market price for Palladium by the expected percentage contained in the karated gold. $200 market at 12 % Pd is $24 per ounce of alloyed gold in added cost as compared to nickel white gold.
Palladium gold melts at 2000F or higher. This can cause problems for ordinary investments. Some casters use a platinum investment which easily handles the extra high temperatures in nickel or palladium white golds. I suggest a starting point as 2050F for casting our palladium white golds. We sell SuperSonic for this purpose.
Palladium does not fill as well as yellow gold, so sprue accordingly. I suggest big sprues arranged for the lowest workable flask temperature at casting, hopefully about 900F or even less.
You must use palladium based solders on palladium white gold. Otherwise someone sensitive to nickel will get the symptoms of nickel dermatitis from the solder used to make their ring or earring. We do have two new palladium solders for palladium gold. Of course laser weld when you can.
I hope this tech sheet is helpful, please do call with any questions that may remain.