In this episode, we want to show how to shape a half-shell.Â In the first step, we start to beat a metal sheet, creating a significant curvature.Â For the start off the aluminum sheet is being annealed.Â This makes the metal soft and highly malleable.Â We have shown the process of annealing in an earlier episode.
After the metal has cooled of, the edge of the plate is gradually shrinked at constant intervals.Â This pulls the edge up and the result is a plate-like form.Â On a shot bag the plate is now evenly driven with a round hard wooden mallet.Â The sheet metal is now heavily stretched and takes the form of a shell.Â Wrinkles that are brought into shape on the edge, due to the stretching, are repeatedly corrected by hand.Â The plate is beaten until a uniform shape rises.Â If a significant irregularity turns up, it will be processed again.
Although the form looks very rough and dented, the shell can be smoothed out either on a round anvil with a smoothing hammer or the english wheel.Â To do this, an appropriate wheel must be selected.Â The wheel must fit exactly to the shape of the shaped shell.Â The metal shell is now being run through the wheels with Medium pressure on the wheels. Â Bit by bit, the sheet is smoothed by the english wheel.Â We can save the time for the final smoothing, because the metal shaping is processed further on from here.
It is already a clearly curved shape, but there are still some steps up to the final product.Â We will show these steps in the next episode.