In working up a bowl or any similar article or part of an article, the sheet may be either "raised" or "hollowed." The raising process is more particularly suitable to the softer metals, such as lead, pewter, copper, and brass, and is carried out, as shown in Fig. 227, the sheet metal being drawn over the head by working round course after course. The edges of the sheet will wrinkle a good deal, and particular care must be taken, especially in thin metal, that the sheet does not double over, or else the job will be ready for the scrap-heap. To avoid this, work around the bowl gently, and if unduly large wrinkles appear, work them out carefully to the edge of plate. If the job is of copper or brass, it should be annealed two or three times during the working up.

Raising A Bowl 246

Fig. 227.

To obtain a smooth surface and to harden and stiffen the metal the job should be finished off with the hammer. The planishing being done with a round flat or concave-faced hammer on a smooth bullet-head stake, as shown in Fig. 228. The blows should be carefully placed, commencing at the centre and gradually working out to the edge. The surface should not be struck twice in one place; but the hammer-marks should join on to each other. The greatest care must be taken that the sharp edge of the hammer-face does not strike the surface, as it is almost impossible to obliterate marks of this character, and if left on, the appearance of the article is not by any means improved.

Raising A Bowl 247

Fig. 228.

If the surface is to be polished it should be observed that it is free from scale and perfectly clean before the planishing takes place, as every particle of dirt on the surface will be driven into the metal by the hammering, and will be most difficult to remove in the polishing.