How to make Rhodium sulphate / Rhodium Plating Solution

A. Hi Amin. I have never made rhodium sulphate, and can't be of much help except to suggest that you google the subject and spend some substantial time on it ⇨
Dissolving rhodium into aqua regia (certainly not simply sulfuric acid) is not as easy as it sounds. Even in fine powder form, it passivates and stops dissolving. If you choose to continue, and hopefully you haven't risked more than a small test tube of solution yet, google "dissolve rhodium in aqua regia" and really study it; rhodium doesn't fully dissolve without very careful chemical or electrochemical coaching.
Good Luck & Regards,


Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

P.S.: please turn on javascript in your web browser, Amin. Proper interaction with websites these days requires it; your messages got to us in fractured form, and we hope we interpreted them correctly and attached them to the thread that you intended.

Do you want to know how to actually make the solution or are you in need of a Rhodium plating setup to plate pieces?

A. Hi, Dirk. Hobbyists might tend to assume that users make plating solutions from commodity ingredients because that's what they saw in science class in school -- but that's not the way it's done 99.9% of the time.

Rather, they buy rhodium plating solution. For one thing, the solution will be nearly worthless if it's contaminated with other chemicals, and rhodium is so fabulously expensive to put at risk that way. I'm confident that jewelers in your area buy rhodium plating solutions and can steer you to a vendor. Good luck!

I don't think you answered Dirk's question.

Hi Gui. You're right, thanks!
Still, the way to Carnegie Hall is practice, practice, practice. With Zinc at $.13 per ounce, Copper $.30, even Nickel at an historically high $1 per ounce, Dirk should at least practice his hand at making other plating solutions first to learn the ropes in the art & science of making plating solutions.

Rhodium metal currently costs $19,000 per ounce -- it's more than half a million times as expensive as zinc. As curator of the forum I feel obligated to warn self-announced hobbyists, before they are inadvertently led down the garden path, that their experiments will doubtlessly greatly reduce the value of their precious metal holdings :-)

Regards,

A. Current density = 1 A/dm2

https://en.wikipedia.org/wiki/Current_density

Hope it helps and good luck!

A. Hi Gui. Dissolving rhodium, even in fine powder form, into aqua regia is not as easy as it sounds. If you choose to go that way, be sure to google "dissolve rhodium in aqua regia" and spend some time on it before proceeding because it doesn't fully dissolve without careful coaching.
Luck & Regards,


Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi Mayur. You're certainly welcome to start with Goran's or Khair's suggested approaches.
But even the industry's trusted sources like Lowenheim's "Electroplating" [adv: this book on eBay , Amazon, AbeBooks] and Durney's Electroplating Engineering Handbook [on AbeBooks or eBay or Amazon] only offer chemical compositions for the baths in terms of "proprietary concentrates".
You might as well ask for the formula for Coca-Cola or MacDonald's special sauce as for the formula for Degussa J2 :-) Good luck.

A. I think Mayur was just asking about the basics.

A. Hi Dhirav. I've already noted that users very rarely attempt to make their own solutions. And two very experienced people have already answered the basic question of how to do it if you insist nonetheless.

Please try your best to frame your ongoing questions in terms of the answers already offered. Maybe the problem is simply that it is complicated like Khair said it is, rather than "simple" like we wish it was? Best of luck.

Regards,

A. Hello Dhirav, I see you asked a question along the same lines a few years ago. The process of taking Rh metal and making Rh sulphate is not easy and should not be attempted by anyone outside of the few companies that do make it. Weigh the Rh that you have. Contact a precious metal supplier that also does refining. They can assay your metal for purity. The supplier should let you exchange the metal for the solution you need. There will be a conversion charge and or a mfg. charge. If you ever have a problem with the supplier's solution you have somewhere to turn and not be pulling your hair out wondering what you did wrong to produce poor results.