A young woman leaves her local jewelry store filled with joy, her husband by her side. A warm, romantic scene to be sure—but this time, it’s not quite what it seems. As the woman stops to open the box yet again, she stares, not at a gift, but at a gleaming brooch that once belonged to her great-grandmother—a brooch that languished in a dark attic until she rediscovered it. Remembering one local jeweler who advertised “restoration” services, she paid the store a visit. The jeweler there knew exactly what her antique needed and had the work finished in a week. Her delight at the beautifully restored brooch would keep her coming back to that little jewelry store for years to come.
With a small investment and a little practice, any retail jeweler can become skilled at using electroplating to restore jewelry. Electroplating is a service that’s easy to offer, it’s something regular customers will use and appreciate, and it’s a profitable way to attract new customers. Additionally, as the appeal of heirloom and antique jewelry grows, so does the demand for restoring original pieces.
Preparing for Plating
When restoring a classic, but rusting, automobile with a new coat of paint, surface preparation is even more critical than the quality of the paint. The same idea holds true for jewelry restoration. With a badly damaged piece of jewelry, it is important to first remove all tarnish, scratches, pitting, and other imperfections from the surfaces. A common misconception is that plating alone, without proper preparation and repair, can restore a damaged piece. Plating over a tarnished, dirty, or blemished surface may actually worsen the damage, because the sparkling new plate of silver or gold may only highlight or exaggerate the imperfections. But if a piece is properly prepared, electroplating is one of the best possible means of restoration.
Plated jewelry may have several layers, so determining the exact composition of the piece you’re restoring is an important step in removing imperfections. A gold-plated piece, for example, may have a top layer of gold plated over a nickel layer, which may in turn cover a base metal such as brass. A silver-plated piece may have a second layer of copper, which then covers a zinc core. This bottom layer, the core metal, is known as the substrate, and this is what the piece is actually made of. Because scratches, pitting, and even tarnish often penetrate all the way into this substrate, it’s important that this core be thoroughly repaired and cleaned for successful replating.
Buffing and tumbling can be used to prepare the substrate for electroplating (avoid sanding or grinding, which may damage the surface). After the piece is repaired, it must be thoroughly cleaned. The substrate must be absolutely free of oils, polishing compounds, dirt, and fingerprints (wearing thin cotton gloves will help). A successful “water-break” test is recommended before beginning the electroplating process (see Helpful Hints).
The Jewelry Electroplating Process
The jewelry electroplating process electrochemically deposits a thin layer of metal (gold, silver, palladium, rhodium, etc.) over a piece of jewelry. The jewelry piece is suspended from a negatively charged clip (coming from a rectifier—the power source) and is then lowered into a plating solution or “bath.” The bath itself is composed of suspended metal ions floating in a glass beaker or other nonconductive container. To complete an electrical circuit, a positively charged anode is attached to another lead and placed into the solution. When the rectifier is turned on and the bath is “live” with the voltage set, the positively charged metal ions are attracted to the surface of the negatively charged piece of jewelry, and attach permanently to its surface. It’s as easy as that!
Plating any substrate metal requires matching the type of metal to the right solution and the proper anode, then correctly executing a sequence of steps. The following are just a few examples of plating procedures—you can find many more, with different metal substrates and finishes, in plating guides and equipment instruction manuals.
To plate gold over a brass/pewter substrate, the jeweler must first apply an ultrathin layer of copper (known as a copper strike) over the brass/pewter, and then pre-plate with nickel before finally plating with gold. Each layer serves an important purpose. In this case, the intermediate nickel plate prevents any tarnish from migrating to the surface, ensuring that the top gold plate remains bright.
To plate silver over nickel, first copper strike the nickel and then place the piece in a bright acid copper bath (for more brightness) before adding the silver plate.
To create vermeil, the jeweler plates 24k gold over sterling silver that is sometimes plated with nickel to avoid tarnish migration (to meet Federal Trade Comission standards, the gold plate must be at least 100 millionths of an inch thick).
Between each of the plating steps, intermediary steps such as electrocleaning, acid dips, and rinses (always use distilled water) must be performed to ensure the highest quality result.
Masking And Pen-Plating
There are times when it’s not necessary (or desirable) to plate the entire surface of a piece of jewelry. You may want to plate only a small design area, create two-tone effects, or make a small repair or touch-up. That’s when masking and pen-plating techniques are useful. In masking, a small area that you want to leave unplated is covered (or “masked”), usually with a special lacquer paint. The piece is then placed in the bath solution, and the lacquer can be removed after plating. Pen plating is an alternative to the bath-plating method described above and works on the same principle by using positive and negative electrical charges and a metal-ion solution. But instead of lowering the jewelry into a bath, the solution is applied directly to a specific area with the tip of a specially designed pen. It is not a substitute for bath plating if restoring a large area is involved. A common example of pen plating is rhodium plating over yellow-gold prongs prior to setting diamonds so that the yellow does not show through.
Have the right equipment and supplies. These include a good electrical rectifier with leads, glass, beakers, anodes, plating solutions, electrocleaner, acid dip, and a good guide. You can purchase all of these separately, or you can get everything you need in one of the many comprehensive plating kits available on the market.
Practice makes perfect. Experience is often the best teacher. Carefully follow all instructions, but also experiment and learn the variables that will affect your particular tasks. Many instructions give recommended bath times in a range (e.g., one to five minutes), so it’s often up to you to know when plating is complete, and practice will provide the experience you need. When you start out, practice on inexpensive pieces and costume jewelry. Try yard sales and rummage sales to find suitable pieces.
Clean, clean, and clean again. The most common cause of plating failure is insufficient cleaning before plating. Most instructions recommend steam or ultrasonic cleaning followed by an electrocleaner bath, an acid dip, and a distilled-water rinse. To check for cleanliness, use the “water-break” test: Dip the piece in fresh distilled water and then remove. If the piece is clean, the water will run off in a smooth, uniform layer. If the water surface spots or breaks off into small drops anywhere, then oils, dirt, or other contaminants remain on the jewelry.
The startup cost of adding an electroplating service is low, and, with some instruction and practice, it’s easy to do. It could become a service that keeps customers coming back.