Hi everyone. I’m an amateur foundryman looking for advice and tips for an upcoming project. I have experience melting and casting fine silver but very little experience working with alloys and fine jewelry in general.
The project is to cast an 18k white gold engagement ring for which I will to propose to my girlfriend later this year.
I’ve been in contact with a local jeweler who will do final polishing, rhodium plating, and setting of the stones. My scope of work is to bring him a cast ring clean enough to work with.
The ring will be cast with gold/palladium alloy. I am not a registered professional or wholesaler so buying premade 18k palladium casting grain is far beyond affordable. Purchasing 24k casting grain and palladium master alloy grain separately is much more affordable and most likely the path I’ll take for the project.
Some questions I have to get started:
When melting and casting a palladium master alloy, can I use a standard equipment? Ie oxyacetylene torch, ceramic crucible, borax flux, kaya cast machine?
Should I use a platinum investment or will a standard investment do the job? I currently have R&R ULTRAVEST and Plasticast investment powders on hand.
When alloying the metals, are there any special deoxidizing agents or chemicals I need to use?
Any advice and pointers for my project would be greatly appreciated! This is my first attempt at something like this.
Hi!
I used to cast palladium white gold regularly before the price of palladium made it too expensive, and it’s not a great metal to begin with, pretty grey in color. I believe that in order to alloy it it would have to be done in a much more controlled environment than the usual torch and crucible, probably under an inert gas shield and with an induction melt. I do know that oxyacetylene is a big no no with Platinum, as it is such a dirty gas that the carbon will contaminate the metal, and I suspect that Palladium is the same. For casting I would use my standard gold casting set up, with a palladium gold specific crucible, a clean quartz stirring rod, and Kerr’s white gold casting investment, which I believe is no longer available and I have switched to R & R’s Ultravest, but I have not cast palladium white gold with that. It would probably be fine, but R & R does have an Ultravest Max for white gold alloys that may be better. Good luck
Cheers!
John
Platinum do not like carbon, it will become brittle and not workable.
So Platinum is best with Hydrogen torch or a very oxidizing flame.
Palladium not so much, but it loves Oxygen and need to be shielded.
It will soak up the oxygen and expel it when it solidifies making bubbles in the metal, just as Silver.
OxyAcetylene with a reducing flame can be used, best will be a electric furnace or induction with Argon.