One of the most important pieces of equipment a jeweller needs is the soldering torch. I use an LPG gas torch. LPG is a mixture of propane and butane.
Nearly every piece requires some amount of soldering. Soldering is the process of joining two pieces of metal together by heating them, using a material of another similarly coloured and structured alloy metal with a lower melting point than the metal being joined.
There are three types of silver solder commonly used:
Hard solder – the highest melting point of between 745-778⁰C.
Medium solder – melting point of between 720-765⁰C.
Easy solder – the lowest melting point of between 705-723⁰C.
As sterling silver melts at 893⁰C, the solder will reach melting point before the silver and fuse the two pieces together.
Flux is painted onto the surfaces to be soldered to prevent oxidization and firescale and ensure that the solder will fuse to the metal. I use borax, which you can see in the dish at the back of my heat resistant blocks.
Paillons of solder are positioned so that they touch both pieces of metal to be joined. The entire piece is heated evenly with the torch to the melting point of the solder, causing the solder to run and join the pieces of metal together.
Once the metal has cooled, the piece is placed in a sulphuric acid solution (which is known as pickle) until it is a white silver colour to remove any oxide and flux, then it is rinsed in water and dried.
This ring is an example of a piece that required soldering. The ring itself is soldered together at the bottom. The swirls and the balls are all soldered individually to the top of the ring.
One of the many joys of silver is that no matter how many times it is heated, melted, beaten, bent, twisted, cut, it maintains the same qualities and substance, so can be repurposed over and over again. I’m proud to say that the supplier I source my silver from manufacture right here in Australia using reclaimed silver wherever possible, so that no unnecessary mining takes place. This recycled silver is refined and tested to ensure that it is 100% pure sterling silver. The planet thanks us!