After the bowl has been raised to a form that is true and even, we are ready for the process of fluting, the first step of which is to divide the bowl into 5, 6, or 7 parts by drawing vertical pencil lines down the sides where the flutes are to come. The above number of divisions is suggested because it is one of the well-known rules of design that it is usually best to divide such forms into 5, 6, or 7 divisions.
Fig. 86 Copper nut-bowls, concave fluting-.
The next step is to make a fluting block, - a piece of some hard wood, preferably maple, about 12" long x 2" wide x l 1/2 " thick, with the end shaped into a flute like that which is to be produced on the bowl, as shown in Fig. 87 The shaping of the wood may be done with a wood rasp and coarse file. Do not try to make the end of the fluting block exactly the shape and size of the flute in the bowl, but make it a little smaller in size and curvature. This is so that you can move the bowl around more freely when you are doing the actual fluting.
Fig. 87. Details of construction.
Fig. 88. Copper nut-bowls, convex fluting-.
Fasten the fluting block upright in the vise with the modeled end up; place the bowl over the end of the fluting block with the vertical pencil line exactly over the flute in the block, and beat the metal down into the flute with the neck hammer, No. 7293,11 as shown in Fig. 87. This will require considerable care and some practice to get a smooth uniform flute. If the metal gets very stiff and hard soften it by "annealing" as described before. When the bowl and the fluting is uniform and true it is ready for the cleaning and "planishing" process.
It will be found that the fluting process has a tendency to draw the top of the bowl in and make it smaller in diameter. Advantage may be taken of this fact to vary the design and get a sharp curve at the edge of the bowl that makes it more interesting.
This tendency of the fluting process to draw in the edge is something to be taken advantage of to produce a better and more characteristic bowl, and should not be taken as a restriction to hold us to a certain form, as sheet metal in the hands of a competent craftsman is manipulated with a freedom and ease which is astonishing in many respects. As an illustration of this, the second bowl, Fig. 86, was raised and fluted in the same way as the first, but the edge was hammered out, giving the section of the bowl a petal like shape.
"See Tig. 37, p. 85.