Blunger

Gladstone Pottery Museum - the slip room - geograph

A blunger is a machine commonly used in the

pottery Pottery is the process and the products of forming vessels and other objects with clay and other ceramic materials, which are fired at high temperatures to give them a hard and durable form. Major types include earthenware, stoneware and po ...

industry for mixing slip, a mixture of

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay part ...

and

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...

. A blunger usually consists of a round or octagonal tank with a mixer. Clay is added to the water-filled blunger and then mixed into a

slurry A slurry is a mixture of denser solids suspended in liquid, usually water. The most common use of slurry is as a means of transporting solids or separating minerals, the liquid being a carrier that is pumped on a device such as a centrifugal p ...

, which is also called

slip Slip or SLIP may refer to: Science and technology Biology * Slip (fish), also known as Black Sole * Slip (horticulture), a small cutting of a plant as a specimen or for grafting * Muscle slip, a branching of a muscle, in anatomy Computing and ...

. The electrical charge of the clay particles is neutralized by the addition of a

deflocculant Flocculation, in the field of chemistry, is a process by which colloidal particles come out of suspension to sediment under the form of floc or flake, either spontaneously or due to the addition of a clarifying agent. The action differs from ...

, which assists in keeping the particles in suspension. This slip can be then sieved as it is emptied from the blunger. In the potbanks around Stoke-on-Trent the blunger was fed by the "sliphouse blunger charger", who was often assisted by the "sliphouse blunger charger's mate". Different types and amounts of clay and marl had to be shoveled in manually to be mixed with water. Blungers are often used in the

kaolin Kaolinite ( ) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is an important industrial mineral. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahed ...

mining industry to mix certain grades of

clay with water. Pottery {{Ceramics-stub