Re-Tipping Prongs with Solder

Sitting at your bench one day, you reach for the next repair envelope, examine the contents and read the instructions. The envelope says, Name: Mrs. JB Tipton. Article: Lady’s yellow ring marked “14k” w/3 clear brilliants, approx. 3.2mm.
Tips on all prongs are worn. Size 5 1/2. Instructions: Retip all with solder.”

You inspect the ring and the gems, comparing them with the description and at the same time troubleshooting for problems that might show up when you begin work. Your experience confirms that the ring is made of gold. The stones appear to be relatively clean diamonds with no sign of treatment; therefore, they should withstand the heat of careful soldering without a problem. All the prongs are well worn, to the point where all that remains are thin slivers of metal to hold the stones in place. You check with a loupe to make sure there’s still some metal over the stones, which is necessary for the solder-only retipping procedure. Since the prongs are so thin, you place the ring in a closed “tea basket” and into the ultrasonic bath. Should a stone loosen and fallout, it will be trapped within the basket.

Then you notice the name on the envelope and recognize it as the wife of the city’s wealthiest entrepreneur and a regular customer in your store. The instructions direct you to retip with only solder. At first you are surprised that this well-to-do customer has chosen the more economical repair procedure. But you know that this method is far more economical and virtually as durable as retipping with solid metal. And then that slogan goes through your head, the one you hear on the radio for Tipton’s Department store: “We stretch your dollar farther.” With a credo like that, no wonder Mrs. Tipton opted to save a few dollars and retip her diamond ring with solder.

When it comes to jewelry repair, there are nearly as many different ways to accomplish a task as there are tools on a jeweler’s bench. In a case like this, where only the tips are worn, prongs can be rebuilt with the addition of small amounts of hard solder that matches the setting (14k yellow hard for 14k yellow gold, etc.). While most jewelers today prefer to add a new piece of gold in the form of wire, pellets, or strips to existing tips, retip with only solder has some advantages to consider. It’s more economical because less gold is used. It’s also much faster-another money saver. When done correctly, the solder method is indistinguishable from the “preferred” method of adding pieces of gold. But unlike the method of adding metal that has to be filed to shape, solder tips can be rebuilt with just a torch, resulting in perfectly formed hemispherical tips that require nothing more than polishing.

Retipping the “Tipton. ” Using the “Tipton” ring as an example, here’s how to re tip the prongs using solder rather than precious metal:

1. This is a common type of cast gold ring with three “fish tail” diamond settings. The name is derived from the shape of the prongs on the side of the setting. As in all settings, the abrasion of daily use eventually wears down the metal so that the stone is no longer secure. No matter what style of setting is used, it’s only a matter of time before the metal wears down.
2. Clean the ring and diamonds in an ultrasonic bath, followed by steaming. You observe that the prongs are not worn evenly; those in the center are more substantial, and those on the ends-which are more exposed-show the effects of greater wear. In order to use the solder-only method, it’s important that some metal remains over the stone; otherwise, there will be no place to attach the solder and you will have to use a different retipping procedure. Begin with a fine-cut flat needle file to trim down the larger prongs so they match those on the ends. Filing the tips down evenly will make the job of placing the solder and winding up with identical tips much easier. Dip the ring in firecoat (a boric acid and alcohol solution) and ignite so that a fine dusting of boric acid coats the surface and the diamonds. Flux the tips of the prongs. Prepare more than enough 14k hard solder snippets for application. A dozen or so will do. The size of the snippets is critical. Snippets that are too small will result in substantially smaller tips that will be insufficient and require a second heating; using too much solder leaves oversize prongs, which require filing and reshaping. Select snippets that are close in size, placing one snippet on the tip of 1 prong with as much surface contact as possible. Spread a few more pieces of fluxed solder onto a charcoal block for use as backups in case more solder is needed.
3. Select a small torch tip and adjust the fuel and oxygen so that you have a very small neutral-to-oxidizing flame, perfect for the pinpoint accuracy needed in retipping. One hand controls the torch while the other holds a solder pick, ready to help direct the solder or perhaps pick up an additional piece of solder if needed and place it on a prong. Keep in mind that solder flows toward the heat. Slowly warm the ring, being mindful that the stones are sensitive to thermal shock. When the entire ring is warm, focus the heat on the top. Begin at one end of the ring, using the torch to warm the solder on one tip to its melting point, whereupon it begins to flow onto the tip. As it flows, direct the solder with the torch, drawing it where you want and controlling its shape as well. Overheating at high temperatures or for too long usually results in pits so be cautious and stop as soon as the solder flows into position with a rounded top. With experience and practice, you’ll find it easy to create solder tips that are perfectly shaped, requiring neither filing or cleanup.
4. After heating, allow the ring to cool slowly; do not quench, because the thermal shock will damage the stones. Examine the job, checking to be sure that each prong is shaped correctly. When satisfied with your work, pickle the ring to remove flux, oxides, and boric acid. Then rinse and dry the ring. If needed, the shapes of the tips can be refined with fine needle files, abrasive wheels on the flex shaft, and/or cup burs. Occasionally a graver or saw blade is helpful in trimming the new tips. As a final step, use a cup bur to trim the tips so that they’re uniformly sized. Buff the tips with a bristle brush on the flex shaft. Clean and then polish the entire ring with rouge, then clean and prepare for customer delivery. With its rebuilt prongs, this ring now looks like new.

JCK, January 2001
Alan Revere

The procedures shown in this article are standard practices for bench jewelers at this time. If not executed properly however; they can cause harm. Neither the author nor publisher is responsible for injuries, losses, or damage that may result from the use or misuse of this information.

The Lone Solder

Regarding the use of solder alone for retipping, Torry Hoover of Hoover and Strong, says that the comparative difference in wearability between gold and matching hard solder is negligible. He explains that 14k gold (whiter or yellow) and 14k gold hard solder (matching in color) will wear virtually the same over time. However, nonplumb solders (such as 13.5l, which once was acceptable for use on 14k gold), repair solder (generally at least 4 karats lower in content), or lower-flow-point solders (easy or extra easy) will not hold up as well as the original plumb karat gold in the setting.

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