Some fundamental jewellery soldering techniques

Most soldering failures are a result of not understanding a few basic concepts about metal, heat and torch control. Until you grasp a few fundamental principles about how heat, solder, flux and metal interact, your work with a torch is likely to yield melted bezels, solder that won’t flow, joins that fall apart, or accidental reticulation. You aren’t alone if you’re bewildered by cryptic instructions such as “place solder on join, heat and pickle”. Here are some basic tips to improve your soldering techniques.

The Basics:

-          Solders are alloys that melt below the melting point of the metal being soldered. When metal is heated its composition of crystals move apart, creating microscopic spaces. Solder flows into these spaces and then bonds to the metal crystals.

-          The area of the metal to be soldered must be clean so that the solder flows. Clean only the metal area being soldered, not the whole piece; this saves time and the solder won’t flow onto the dirty metal where you don’t want it.

-          Flux prevents oxides from forming on metal. (Oxides prevent solder flow).

-          Oxides are surface coatings like tarnish or rust that occur on certain metals when they’re exposed to oxygen.

-          The torch flame does not melt the solder; the torch flame heats the metal to the melting point of the solder.

-          Two pieces of metal being soldered must rise to soldering temperature at the same time, or the solder will flow to the hotter of the two metal pieces, rather than along the join.

-          Solder does not fill gaps! Your metal pieces must make a tight fit at the join.

Choosing the Right Solder

                As Handmade Jewellery makers you’ll most likely encounter silver and gold solders. The most common grades (heat ranges) for solder are easy, medium and hard. When soldering dissimilar metals, select a solder with a heat range that is appropriate for the metal that has the lower melting point. Use brass brazing rod or silver solder to solder steel and iron.

                Use silver solder for sterling or fine silver metal sheet and wire. For fine silver metal clay it is best to use hard solder for the best colour match. Fine silver melts at 961 degrees C and hard solder flows at about 777 degrees C, depending on the manufacturer. Because metal clay is more porous than metal sheet, be sure to burnish the metal clay to compact its structure prior to soldering it.