Thistle Pots – The making process

To cause metal to move as one works, through select application of force is immensely satisfying.  It is extraordinary that this material can be manipulated in this way.  One can understand that the atoms within the element are given space to move through the application of heat and caused to do so when compressed between hammer and stake. The resultant transformation from flat to almost limitless shape defies any kind of logic, as the material can be made to stretch and contract in ways that seem impossible.

Raising is a process of forming metal through courses of annealing (heating), quenching (cooling), pickling (removing oxides), hammering against an anvil or shaped stakes and planishing (fine surface finishing).  

As an alternative to sinking (hammering into a bowl-shaped former), the flat disc of annealed gilding metal is pressed against a turned hemispherical wooden form in a lathe.

As both pieces spin, the metal disc is forced against the former by applying pressure – resulting in a bowl shape

The courses of annealing, pickling and tooling begin and the shape develops.

Annealing (heating the workpiece to a glowing red hot form) expands the metal creating space for the molecules to move. The hot workpiece is dunked into a pickling solution which removes the outer oxidised metal layer to leave a clean surface for working.

If the metal form is allowed to air cool it sheds an oxidised layer

Leaving fine and fragile flakes

After several hours the shape has transformed from bowl to bulb shape (anticlastic).

They have now been pinched in and are beginning to be drawn back out again (synclastic)

Many more courses later and the circumference of the edge of the original metal disc has now been reduced by a quarter.

The edges become thinner and more prone to splitting. Still a while to go yet

A finished thistle pot.

See the Thistle Pot collection here