Non-ferrous base metals have recently seen a growth in popularity amongst jewellers due to their increased reactivity, useful working properties, and lower prices when compared to precious metals. The most commonly used are copper and brass, however jewellery makers also turn to bronze, zinc and gilding metal for practice.
- The above base metals can all, except for zinc, be soldered using silver solder and borax. Copper is more difficult to solder because of its tendency to oxidise;
- Their reactivity allows for a wide range of colouring techniques to be used;
- Their surface is usually quickly to tarnish in air;
- Cannot be hallmarked or used in pieces that will be hallmarked.
Copper has a warm orange colour when polished however,due to its increased affinity with other metals, its colour changes easily from brown to purple, blue or even black effects. One of the disadvantages of wearing copper jewellery is that it can leave skin green. When exposed to certain atmospheres copper turns to a shade of green or blue. It is often used to strengthen gold and silver. To protect it from corrosion, jewellers oxidise and seal it securely. Use Anti-Tarnish Tabs and Bags to keep your copper, brass and other non-ferrous and ferrous metals secure.
-
-
Copper Sheet
-
-
Gold and Silver Plated Copper Wire
-
-
Anti-tarnish zip-lock bag
-
-
Anti-tarnish non-abrasive tab
Brass contains 60% copper and 30% zinc and it has a higher melting point than both its constituents – 921ͦC – 960ͦC. Brass requires frequent annealing and air cooling to avoid cracking. If the copper quantity is increased its colour becomes more golden and the metal more malleable. It represents a good choice when working wire structures due to its rigidity after it has been hardened. It is suitable for tools designing –punches, pierced templates e.t.c.
Gilding metal has a warm yellow colour (given by its composition of 95% copper and 5% zinc) and similar malleability and working properties to silver, with a melting point between 899ͦC – 941ͦC. As with the other metals, it is often used to test run pieces to keep the material costs to a minimum.
Bronze has a yellow brown colour and is mostly used for casting due to its increase hardness and ability to retain details.
Note: Nickel also belongs to the base metals category but it should not be used in jewellery making as the chances of an allergic reaction are high.
What other metals do you turn to and what have you learnt from using them?
