Soldering is essentially the fusion or joining together of two pieces of silver by the application of heat melting a solder. When heat is used to melt together two piecs of silver without solder then it is welding.
- Annealing. - Make sure the silver is properly annealed. see annealing silver jewellery.
- Cleaning. - It is absolutely essential that before you begin the silver is thoroughly cleaned. Even very small amounts of grease or tarnish will ruin the soldering. Make sure that you have good flux and also ensure the solder itself is bright and clean as it will flow more quickly and easier.
- No Gaps. - It is also vital that there are no visible gaps between the two pieces you want to solder. This is to prevent the solder from running down one side of the seam. Solder has a capillary action.
- Flux. - The best and most cost effective flux is Borax. The purpose of flux is to help the solder flow and prevent oxidation.
Make a white paste by grinding the borax cone into a dish with a little water.
Brush on the Borax paste onto the two pieces you want to join. The photographs illustrate making a silver ring however the same method can be used for almost any item of jewellery that requires soldering.
Cut out a small piece of solder. (paillon) For making this ring we are using easy solder as there is only one joint. For more complex welds start by using hard solder then apply medium and then finally the easy. Place the small cut just below or on the joint.
Heat the piece gently using a titanium stick to occasionally reposition the item. make sure the solder stays in position. Make sure you direct the heat at the piece and not the solder itself which will naturally heat through conductivity.
When the solder has become shiny and run along the join, remove the heat and let the item cool for a few seconds.
For keeping awkward or large pieces together use binding wire. You can also use a long strip of solder instead of a paillon. This is known as stick soldering. If you want to prevent the heat from conducting to other areas of the item, for example chain making, then isolate the area that does not need soldering. One method is to leave that area in a dish of cold water. As regards gemstone set rings then generally the gemstone will have to be removed before soldering, otherwise the silver will conduct the heat that will damage the gemstone.
Finally quench the item in a bowl of pickle and then rinse with water.