Repousse and chasing are synonymous terms for the same kind of work and process. Repousse is the French term, and chasing and chased work are the English terms. As the term chasing is that which is in common use in the trade, and in the supply catalogs the tools are designated as chasing tools, it seems best in this book to use that term.
Fis. 131. Silver cup, flat chasing, showing- the extent to which simple chasing may be carried.
In chapter XIV (Outline Chasing, Raising) instructions were given for the most elementary method of chasing - that is, chasing on a piece of soft wood instead of pitch. Chasing is sculpture in metal; it is the fine art of metalworking; it is the making of bas reliefs in metal, and it requires training and ability to see and think in three dimensions. Saw-piercing and engraving require only two dimensions, length and breadth; chasing requires the third, thickness.
An explanation of the technical processes of chasing is very simple and is easily understood. The metal with the design drawn on it is embedded in chaser's pitch, and the design is outlined with a chisel-like tool called a "tracer." The metal is then removed from the pitch, placed face downward on a piece of soft wood, and the raised parts of the design are beaten up from the back. The metal is then "annealed" and placed back in the pitch. The design is then modeled into shape with the proper tools.
The chasing tools used are made of tool steel 1/8" or 3/16 square and 4" long. A well selected set of 50 chasing tools may be bought from a dealer in such tools for $7.50. But it would be just as well for a beginner to buy a straight and a curved tracer, a large and a small planisher, learn to use them, and make the others as he needs them. When making them, after they have been filed to shape, they must be hardened by heating the points red-hot and plunging in cold water. They are then polished bright with emery cloth and tempered by slowly heating them to a dark straw color and again plunging into water. Chasing tools may be roughly divided into four large divisions: tracers, straight and curved, that are used to make lines; planishers, of numerous shapes and sizes, used to beat down the background and for modeling; matts, similar in shape to the planishers, but with matted or grained surfaces which are transferred to the metal when the tools are used; beads, rosettes, and special tools that are not of any great value to the beginner. A box of chaser's tools is shown in Fig. 134.
Fig. 132. Chased flower jar, "traced and snarled." This photograph shows the preliminary steps in the work, which is shown completed in Fig. 126.
Chaser's pitch is made of equal parts Burgundy pitch and plaster of Paris melted together. To every 5 pounds of combined pitch and plaster add a piece of tallow the size of an English Aval-nut. Melt the pitch first, and slowly add the plaster, stirring it in as you add it to the pitch.
Fig. 133. Chased flower jar, background beaten down. A later stage in the process.
For large flat pieces the pitch may be poured into a square cake tin, or an ordinary bread tin. For small, fine work it is better to use the round pitch block and ring, shown in Fig. 134. A cheap pitch block can be made from an ordinary pudding pan about 6" or 8" in diameter. The bottom should be beaten out round, so that it will set firmly in the ring and be readily turned and tilted when necessary.
A chaser's ring is a ring that holds the pitch block in position while the piece is being chased. A very satisfactory one may be made by taking a piece of copper 2" wide and about 20" long and riveting or soldering the ends together so as to form a circle. Then wind around this ring strips of cloth until the pitch block fits in snug and tight, as is shown in Fig. 134.
Fig. 134. Chasing- on pitch. Pitch block, chasers ring, tools, and method of holding tool.
After the design is drawn or transferred on to the metal, the edges of the metal should he turned under with a pair of pliers, and then placed on top of the pitch and warmed with the flame of the blowpipe or Bunsen burner. The heated metal will slowly sink into the pitch. Care must be taken that the metal is not too hot, as it is likely to sink in too far. When the metal is cold, start to chase the outline with the tracers. Be careful to hold the tool in the position shown in Fig. 134, with the fourth and third fingers resting on the metal, the second and first fingers and the thumb holding the tool. Do not hold the tool perfectly straight, but tilt the top slightly away from the direction in which you want to move.
Wig, 135. C hased cover, with stone set in center.
The first attempt at tracing may be a failure, but after an hour's practice control will be acquired. The right-hand side of Fig. 128 shows a student's first attempt at tracing. Fig. 131, a silver prize cup, shows the extent to which simple tracing can be carried.
The left-hand side of Fig. 128 shows the next step, which is beating down the background with the planisher chasing tools. This is sometimes done instead of beating up the design from the back. An application of this method is shown in Fig. 129, a chased copper plate. But in the case of the blotter, Fig. 130, both methods were used. After the planishing of the background, the metal was removed from the pitch by warming it slightly and lifting it out with a piece of wire. It was then annealed and the design beaten up from the back on a soft piece of wood, set back in the pitch, and modeled to form with the small planishers. If the design is beaten up very high, it will be necessary to fill the high places with pitch before setting back in the pitch pan, as the air is likely to become enclosed in the high places and the metal will sink when an attempt is made to chase it.
The chasing on the flower jar, Fig. 126, is also a student's first attempt at chasing. Figs. 132 and 133 show the earlier steps on the same piece. To raise the design on pieces like this it is necessary to use the '"snarling iron."14