I’ve been asked what kind of equipment is used in then professional gold plating of jewelry. Having gold plated jewelry for years for my clients, with a little help from my plater friends, I decided to go “back stage” and take you with me!
In this post I’ll give you a peek behind the scenes at the equipment that is used in gold electroplating.
In order to help you understand plating better, I’ll also, with the help of K.V., give you some technical info about it. Let’s take a walk inside the workshop together. See my earlier post on “Gold Plating Jewelry Explained – How Plating Renews Your Old Jewelry.” Super quick before we start, I’d like to make sure that you know there are two different methods of ‘golding up’ your jewelry. Jewelers can gold plate your chain, your ring and pieces of jewelry. However there is another process out there called PVD coating that is used on costume jewelry, especially watch bands that is different and not the topic of this post.
The Basic Principles of Plating
Plating describes surface-covering where a metal is deposited on a conductive surface, like gold over silver. Plating has been done for hundreds of years, but the years have improved the techniques, equipment and access to it.
Plating is used to decorate objects, for corrosion inhibition, to improve solderability, to harden, to improve wearability, to reduce friction, to improve paint adhesion, to alter conductivity, for radiation shielding, and for other purposes. Jewelry typically uses plating to give a silver or gold finish.
Doing it Right For Safety and Great Results
There are four basic best practices for the best plating results.
1) The first one is temperature control. Plating results are the best when the temperature is kept at a constant high temperature.
2) Another factor necessary to successful plating is voltage control. Plating needs to occur at a certain electrical level, and the voltage must be tightly controlled.
3) Cleanliness of the liquid is also a factor in the success of gold and other metal plating processes. Ideally, plating baths are constantly filtered to remove dirt and contaminants. This means that a plating bath can be used for years. Then the water can be allowed to partially evaporate and the remaining can be sent to a refinery to be filtered clean to keep it environmentally cool.
4) Great care is taken with excellent ventilation and different rooms for different plating processes. This is for the health of the plating professionals.
The Positives and Negatives of the Plating Process (It’s a Pun)
The items to be plated are hung from a cathode bar. It is a pole with a negative electrical charge going through it. The pieces of jewelry connected to the cathode bar are also negatively charged.
When the jewelry items are submerged in the tank the electricity is turned on and the negatively charged jewelry attracts the positively charged ions present in the liquid.
The positively charged metal ions are submersed in the liquid bath. When the cathode bar is lowered into the bath the metal jewelry gets plated using this positive and negative science of attraction.
Different plating tanks are used to plate different karat amounts and different metal colors. The same tanks are used to plate the same metals over again. That’s why there are so many tanks.
First Step to Plating – Preparing the Surface to be Plated
The metal to be plated must be very clean, with no oils or dirt. This is necessary for two reasons:
A) dust and dirt interfere with the plated metals adhering to your piece, and
B) to keep the plating tanks free of contaminants.
Second Step to Plating – The Final Cleaning Step
We always want to be totally sure that your piece of jewelry has the best chance for an excellent plating result.
Steam cleaning blasts off any oils that managed to hang on during the polishing phase.
More intricate jewelry takes longer to prepare for successful plating, so expect to pay more if your jewelry has many nooks and crannies.
Third Step to Plating – Rinsing
Now that we’ve done all this cleaning, we need to make sure there is no cleaning chemicals left on your gold.
Fourth Step to Plating – Immersion in the Plating Tank
With the time, temperature and voltage carefully controlled your chain dives down into the liquid, and is deliciously covered in bright happy ions of gold.
When the timer dings, your piece is done, out it comes, brighter, gleamier and prettier. Otherwise, why do it?
Fifth Step to Plating – Rinsing
Once rinsed they are dried and ready to go.
Additional Steps to Plating – Using Other Metals
Sometimes plating takes more than one plating immersion. Sometimes other metals are plated first to create a barrier between the original metal and the final metal to make a longer lasting bond.
Sometimes with costume jewelry the base metal would contaminate the tanks with the gold in them. So a different metal is plated prior to the gold plating.
There are little steps I’ve left out because it is repetitive and this is not an instructional how-to as much as a this is basically what is done.
End of Tour
I hope you enjoyed your armchair field trip to the gold plating palace!
My thanks to K. V. for answering my barrage of questions. “Do people really want to know this stuff?” he asked me. Let me know in your comments if indeed people want to know. I’ll tell him.
Gold Plating Jeweler,