AS Product Design - 10.5i Forming metal - beating

Hollowing

A procedure used to produce shallow bowl shapes from circular sheet metal blanks

Annealing

heating the metal to a dull red and therefore malleable

Annealing for aluminium

it cannot be heated to red heat because it never glows red. Soap should be rubbed onto the surface, and the metal heated gently until the soap turns a dark brown, the correct temperature has now been reached for annealing. The burnt soap can be washed off with water

Forming a hollow shape

1. Use a hollowed hardwood block, or a moulded sandbag

2. The metal disc is placed at a shallow angle and is hit with an egg-shaped Bossing Mallet.

3. After each blow the disc should be rotated one space, so the next blow lands beside the first. Starting from the outer edge, spiral into the centre. The bowl shape will form automatically

Sinking definition

a procedure that can produce a shallow bowl with a lip around the top edge and a flat base

Sinking procedure

1. The metal disc is placed against both dowel pegs. The edge on the top surface of the sinking block remains horizontal and produces the lip.

2. A blocking hammer is then used to create the hollow shape

Planishing

procedure that is carried out after hollowing or sinking to remove unwanted bumps and correcting the overall shape, as well as hardening the metal.

Planishing procedure

Starting in the centre, the bowl is revolved one space after each blow. The blows should spiral outwards to the edge