Making silver jewelry often involves soldering one or many pieces of metal together to form shapes and create intricate patterns and details. Filigree jewelry, which is composed of tiny curlicues of metal set inside a heavier frame of metal wire, requires plenty of soldering. Because the metal pieces are different gauges of thickness, it’s helpful to work with more than one type of silver solder so the finer silver pieces don’t melt when you're soldering them together with a torch.
Content and Melting Temperatures
When you’re making a piece of jewelry with multiple parts, you’ll need to solder in stages, and that can affect which type of silver solder you decide to use. There are three basic “hardnesses” of silver solder: hard, medium and easy. Each type has different quantities of silver in it — along with other metals, such as cadmium and copper — which affects how quickly it melts. Hard solder is composed of 75 percent silver, with a melting temperature of 1,365 degrees Fahrenheit. It can take more heat than easy solder, for example, which is composed of just 45 percent silver, and has a melting temperature of 1,145 degrees Fahrenheit.
Sheet solder is exactly what it sounds like. It’s a thin sheet of silver-metal alloy that’s commonly used by silversmiths. As described in Section 1, sheet solder is available in various hardnesses, and can be cut into small chips -- called paillons -- and heated with a torch to join metal pieces together. The benefit of cutting your own sheet solder is that you can make the pieces as large or small as you like, which makes it easier to use the solder for its decorative nature. For example, some jewelers will melt a chip of solder to a piece of copper to provide contrast. Since sheet solder has less silver than a sterling silver sheet, which is composed of 92.5 percent silver, it’s a cheap option for making inlay. Sheet solder needs to be used with a commercial flux — borax — in order for it to melt.
Silver solder wire is sold in a coil, and its diameter is usually 0.3 mm. Similar to sheet solder, it comes in three different hardnesses. Some jewelers prefer using wire solder instead of sheet solder because it’s easier to control the amount of solder you use, but you have to be more precise. When the metal piece is heated, the tip of the wire solder is touched to the join. A small bit should melt to make a tidy join. As with other silver solders, wire solder doesn’t just need to be used with silver. It can also be used to join copper and brass pieces together. It will, however, look silver in color.
Jewelry making often seems to delve into the world of mad science, especially when you see how paste solder is sold: in a syringe. This odd concoction is actually a smart shortcut. The solder and flux are mixed together in the syringe, which makes it easy to dispense exactly how much solder you need, exactly where you need it. You can buy hard, medium and easy paste solder.