My clients often wonder and ask us how their rings are sized so I thought it would be fun to cover the process in today’s blog.
Ring sizing is one of the most common repairs done on jewelry. Ring sizing therefore should be a manageable task for a skilled jeweler. Whether it’s made of sterling silver, gold (in any karat), or platinum, ring sizing is generally gone about in the same manner.
Methods to Size a Ring
There are a few different methods in which a ring can be sized. Typically, a piece of metal is added or removed from the bottom of the band, technically known as the shank, to change its size. When you think about it a ring is sized by changing the diameter.
A ring that does not contain stones can alternately be stretched or compressed. This sort of sizing is typically done on men’s bands. To stretch a ring to a larger size, the ring is placed on a steel mandrel that expands from the inside, and it is slowly stretched to the correct size. This process slightly thins the thickness of a band. To compress a ring to a smaller size, the ring is placed in a series of die-cut cylindrical forms in descending size. The ring is pushed into each die until the desired size is reached. This process slightly domes a band.
Another option for stretching a ring is to hammer the shank of the ring to increase the size. This should only be done if the ring is in need of a minor adjustment. Sizing a ring in this manner is generally only safe when a half a size adjustment or less is needed. When such a small adjustment is needed this may be a good choice depending on the ring style. It should always be at the jeweler’s discretion to decide what method will be used when sizing a ring. Though the customer may think that stretching a ring sounds better than cutting, it is not always the case!
In order to size a ring down the jeweler will remove metal by cutting out a precisely measured piece from the bottom of the shank. The measurement is dug into the band with a scribe and the cuts are then made using a special jewelers saw blade. Once the metal is removed, the jeweler uses pliers to bring the two ends back together. The jeweler works to achieve 100% contact where the two ends meet, he/she then makes sure the joint is clean of dirt and oil and then the ring is ready to be soldered back together.
Unlike welding, when soldering, large gaps between the metal cannot be filled to join two pieces. When it’s done correctly it actually re-weaves the crystal structure to join the two pieces instead of joining two pieces with solder or electrode which is how welding is done.
Now that the two surfaces are clean we can begin soldering! The ring is first dipped into a boric acid solution called fire coat. This solution will help protect the ring from oxidation which happens from the flame during the soldering process. Then the ring is positioned on a soldering board and flux is added to the area to be soldered. Flux helps the solder flow once it is appropriately heated. Next a small piece of solder is positioned on the joint and finally an even heat is applied with a torch, making sure to bring up the temperature of both sides evenly. The ring will begin to glow red which is so cool to see!! Just before the solder flows the surface will become very shiny. The ring then is re-rounded, filed to remove any excess solder and then brought to a high polish to remove any oxidation that has covered the ring and so that little to no evidence of the sizing remains.