Wednesday, 1 May 2013

Inlaying of Jewellery

1 Brass sheet with contrasting silver wire; 2 chisel type gravers with different-sized cutting edges; 3 large punch for tapping wire into grooves; 4 wooden handles for graver chisels.

Inlaying


Fine metal lines can be laid into contrasting metals or into other media, such as wood, to produce intricate patterns and designs in a finely finished surface. The traditional method is for the inlaid metal to be held in channels or grooves that are chiseled from the background metal. The grooves are cut in such a way that a burl is raised on each side of the cut; these burls are pushed down and burnished over the fine metal wire that is laid in the channels.

There are some remarkable examples of extraordinarily detailed Japanese metal inlay work, and it is worth looking in a museum to see some of the finest work of this kind.

The technique illustrated here will enable you to achieve the same effect without having to master completely the skills of accurate chisel and tool work that are essential for traditional inlay work. It is, however, important to understand the principles underlying the traditional method by which fine wire is laid into the surface of another metal.

The metal


Use a metal that contrasts well with the wire that is to be inlaid. The metal should be 1/32 inch thick, so that a deep enough channel to accommodate the wire can be cut without a mark appearing on the back when the wire is hammered in. The thinner the metal you use, the finer should be the wire that is inlaid.

Draw the pattern to be inlaid on the surface of the silver. The metal should be annealed and then held flat in firm pitch or in jeweler's wax. The lines for inlay should be transferred directly onto the metal by tracing through the design, or by marking the metal with a pencil or scriber.

The wire


You can use either round or rectangular wire. It should be well annealed and fit closely into the channel. Fine silver and gold wires, which are soft and flexible, are ideal for inlay work, but whatever you use must be a strong contrast with the background metal.

The tools


A chasing hammer is used to hit the top of the chisel as it cuts into the metal. The chisel is held at the same angle as a tracing punch that is, it is held between the thumb and index finger of one hand, with the handle pointing away from your body while your other fingers rest on the metal. The chisel is worked toward you along the prepared line.

The cut, which is the essence of inlay, must be undercut. This means that the edges are raised slightly during cutting so that when the wire is laid in position, the edges are hammered down and so hold the wire in position.

Use a punch that is no wider than the wire that is to be inlaid and, holding the punch above the work, strike it with a medium-weight hammer. Work smoothly along the lines of the design, overlapping each stroke as you make the next one.
The chisel has a cutting edge, of which the bottom edge is somewhat ground away to enable a very fine line to be cut. Chisels used for cutting metal do not have wooden handles, like those used for working with wood. The handles are made of steel stock, and the cutting end should be tempered.

A matting or embossing punch is used to beat the wire into the channel. It is held vertically above the wire and hammered with a chasing hammer or a heavier hammer if necessary. The face of the punch must be wide enough to spread across both the inlaid wire and the raised edges of the channel.

The groove or channel can also be cut with engraving tools. The first line is cut with a graver with a lozenge-shaped head, and the base of this line is broadened by a flat-edged graver. Wire can be punched into the groove, but it will need to be held in place with solder because there is no raised edge to push down to hold the wire in place. Use the smallest possible amount of solder and file the surface level after soldering.

Inlaying the wire


Place one end of the wire at the start of the chiseled groove and tap it into place with a punch to make sure that it is held firmly. The wire is then inserted gradually into the line, pressed into place by the punch as you work along the channel. The main object of the process is to push over the edges of the groove that were raised during chiseling. When the wire has been pushed into place, a burnisher can be used to smooth the top of the wire and any rough edges.

If you are using a rectangular wire for the inlay, burnish along the bottom edge to create a slight overhang that will fit snugly into the chiseled groove.

Writer – Jinks Mcgrath

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