Soldering is an essential technique in jewellery making and silversmithing, allowing you to join metals with precision and durability. One of the most crucial elements in successful soldering is soldering flux. Without flux, soldering becomes a challenge, resulting in weak joints, poor adhesion, and tarnished metal. In this guide, we’ll explain the role of soldering flux, why it’s so important, and how to choose the right flux for your projects.
What is Soldering Flux?
Flux is a chemical agent applied to metal surfaces during soldering. Its primary function is to prevent oxidation and improve the flow of solder. When metal is heated, it can oxidise quickly, forming a barrier that prevents the solder from bonding effectively. Flux helps eliminate this barrier, ensuring a clean, strong connection.
In addition to preventing oxidation, flux:
- Cleans the metal surface by removing impurities.
- Promotes smooth solder flow for even coverage.
- Reduces the chances of solder joint failure.
The most popular option is liquid soldering flux. This is ready-made and can be dropped straight onto your jewellery piece, making it a quick and easy option.
The more traditional option is a borax cone and tray - the borax is dampened in the tray with a little water to create a thin paste which can then be applied with a brush.
Paste flux is also an option for the professional jeweller, allowing you to apply precise lines to joins. This combines the solder itself with the flux.
Soldering flux is an essential tool for anyone working with metal. By choosing the right flux and applying it correctly, you’ll create strong, reliable joints and produce beautiful, professional-quality work.