Ring sizing is one of the most common procedures performed in our repair shop. For such a common task, most people don't know how the work is done; many have probably never thought much about it. Rings are often one of our most sentimental and treasured possessions so understanding what goes on during the process could ease your mind next time you find a ring fitting a little too snug.
The first thing we do is give your ring a good cleaning. When a ring is sized it is heated and when it is heated any residual lotion, dirt etc can start to burn and cause problems such as solder not flowing where it needs to go and making the ring much harder to clean later.
Once the ring is clean the process differentiates slightly based on if the ring is being sized up or down. Sizing down is usually a simpler procedure. Two cuts are made in the bottom of the ring to remove the correct amount of metal to size down the desired amount. Often times we can tell where a ring has been sized before and can re-cut a prior solder seam in order to prevent adding additional seams to the ring. Once the correct amount of metal is removed the sides of the ring are brought together until they match.
With sizing up, the ring is cut in only one area and the ring is opened up to accommodate the correct amount of sizing stock. Sizing stock is a piece of metal in the same quality as the ring we're sizing. For example a 14k yellow gold ring would receive a piece of 14k yellow gold sizing stock. The sizing stock used is slightly taller and slightly wider than the dimensions of the ring. This allows us to file down the stock to blend into the ring while removing very little metal from the ring itself. If the stock used is too small, the bottom of the ring could end up significantly thinner and thin rings do not hold up well to wear. Some rings are thin to begin with and in these cases customers are made aware ahead of time of potential problems this could create. Sometimes other things can be done to replace the bottom of a ring that is getting too thin.
Once these steps are completed, the metal needs to be soldered together with a torch. The ring is dipped in a protective solution and then each joint is heated to allow solder to flow between the joints and connect each part of the ring. Solder comes in different qualities as well, so a 14k yellow gold ring would be soldered with 14k yellow gold solder. This step requires the steady hands and knowledge of a jeweler. Our experienced jewelers know how much heat can be applied to a ring to melt the solder and keep the ring from being damaged. They also know what stones can take heat and how the job can be performed on rings with stones that cannot handle the heat of the torch.
Some rings require a different method of joining seams. Platinum, for example, is best sized using a laser welder. Platinum reacts very well to the pulse of the laser and can fuse the metal together leaving no seam behind.
Once a ring is soldered it is placed in a bath to remove the glass-like residue left over from the heating process. The ring is then filed, sanded and polished to blend the seam into the ring and make the ring look like new.
Ring sizing is a science and an art. It takes knowledge and skill to perform correctly. Next time you're in our store, take a look through our large windows at the jewelers in the shop and maybe you'll catch a glimpse of a sizing in action.