Wood block
Directions: Take the sheet of copper, and with the dividers mark on the copper a circle having a diameter a little longer than the contour of your bowl design. Cut this circle out with your shears.
With the round headed hammer, using the rounded end, beat the metal disc into the hollow of the wooden block until it takes on a fairly even bowl shape. Keep turning the metal with the left hand while you hammer it with the right.
The long even buckles are easily hammered out; the short, sharp ones are the kind that cause the cracks
You soon have a rough shaped bowl full of bumps and wrinkles around the outer edge.
These wrinkles must come because the circumference of the metal disc decreases as it takes on the bowl shape. So long as these wrinkles are long regular curves, they will work out all right. If they should take short, sharp shapes there is danger of the metal splitting. In order to avoid this be sure to keep the wrinkles hammered out flat as you work along.