kadriver said:
nickvc said:
The English 9k white gold recipe is basically sterling silver mixed with fine gold and inherently will always look a little like a very pale butter colour and be fairly soft, decent 18k white gold can be anything from 10-15% palladium which hardens and whitens the alloy, most repairers will use a rhodium plate to refinish the sizing or repair to an item and most customers prefer that look.
Thanks for all the input. The jeweler has concluded that in order to stay current that he will set up a rhodium plating station. He wants me to help set it up. I have absolutely zero experience with plating.
He has done it in the past, but it was decades ago. Stuller has all the stuff we need, but I'm thinking the kit that they sell probably has chemicals that we can get much cheaper if I just knew what they were.
If anyone has any experience that they can share it would be greatly appreciated.
Thank you,
kadriver
Those jeweler's plating solutions are very simple. Just follow the instruction's to a tee and keep everything very clean. Don't contaminate the solutions with anything - other metals, organic materials, etc. Before the plating itself, cleaning and activation steps are required. Don't contaminate the Rh solution by dragging in these prep cleaners and acids. Proper rinsing between steps is vital. When not in use, cover the solutions or pour them back into their bottles, after cooling. The plating solution vendor should be able to help in setting up proper cycles. Different base metals might require slightly different prep cycles. Many plating problems occur due to a faulty, inadequate, or contaminated prep cycle. The rhodium solution is heated and will evaporate - maintain the solution level with pure water.
In general, as a group, jewelers are the most ignorant of all the types of people that use plating solutions. This is not a criticism. It is because all they need to use are these easy to learn, hopefully never fail solutions that plate super-thin deposits and they rarely need to get into the intricacies required of the much, much more advanced plating systems, such as found in the electronics industry.
I would not shop for price and I would never make the beginners mistake of trying to formulate my own solution. I would select a large supplier that has a lab and has tech service people that are quite knowledgeable about their plating products. A good vendor will help you out with technical problems. I assume they still do this, and solution analysis, maybe, as a free service. I spent several years as the head of tech service/lab guy for 2 of the largest plating solution suppliers in the world and I owned a couple of plating shops. I've been on both sides of the counter. That was a long time ago, but Rh baths are still exactly the same.
Most Rhodium plating solutions are nothing but 2g/l rhodium, as the sulfate, sulfuric acid, and pure water. There are also rhodium phosphate/phosphoric acid and rhodium phosphate/sulfuric acid baths. The maximum thickness of Rh plating is very limited. Typical Rh plating on jewelry is from 2 to 5 microinches thick. Plating time is about 20-60 seconds at 6 volts. Every vendor's instructions are a little different. I would not buy from a vendor that didn't provide good instructions. Rh plating is very stressed and, if you try to plate too thick, the deposit can crack and peel. Here again, follow the instructions. Platinized titanium or tantalum anodes are required - buy them new - they are sold by the square inch. Get a good variable power supply of proper size - no Mickey Mouse battery chargers. If this is just for a ring or two, every so often, a beaker kit would work fine. For greater volume, I would look into a more professional vendor such as Technic.
For this simple plating system, I may be overstating everything. These are the things I would do. Most jewelers don't do them all. If you have questions, please ask them.
