1. This area of the plant was originally used for the manufacture of crocks.
The term "crock" is not familiar to younger people but it brings back many memories among older ones.
Crocks were a commodity item and the main container used to store and process food during the early and middle 20th century. Smaller 1 to
3 gallon crocks were relatively easy to make using the jiggering process and we make reproductions this way today.
'Medicine Hat-made' stoneware crocks were incredibly durable and strong and would
last for decades of hard use.
This 50 gallon Medicine Hat Potteries crock was made using stiffer clay and a special roller device called a 'Weeks Machine'. A large cast iron spinning drum and base assembly were built into the floor and could be raised and lowered. A heavy rounded wooden roller on a pivoting and moveable arm was used to roll the clay against and up the wall of the paper-lined drum. The drum was then lowered out of the way and the crock smoothed and removed. This kiosk is sitting under the pulleys used to raise the upper arm of one such machine. The lower assembly was cemented into the floor during the 1950s. The parts for the upper assembly of a Weeks machine are on display in this area.
Larger crocks weighed up to 300 pounds. While the quality clay available in this area made things easier, the workers also had much to do with the successful manufacture of these amazing vessels. Crocks had to be dried slowly and very carefully to avoid cracking. They were relatively fragile when dry yet skilled workers developed ways to lift and glaze them in large tanks without breakage. Firing them to 2300F required extreme care since uneven temperature rise would produce cracks and warping. In addition larger ones would shrink almost 5 inches (12cm) during drying and firing so they had to be made considerably larger than the final size.
To the left you will find some large posters detailing the mechanics of the Weeks machine and showing Emil Jenke making a crock at Medalta (1966) Limited around 1970. Emil is one of the only living people in this area that is familiar with the unique mechanical workings of this machine.
The term 'refractory' refers to ceramic that can withstand high temperatures. The term 'saggar' refers to ceramic vessels used as containers in which to fire other objects. Whiteware, especially plates, were fired inside stacked saggars to protect the glazed surface from bits of debris picked up by turbulence inside the kiln. Saggars were heavy and required a lot of extra energy and a firing time. By comparison modern factories keep kilns spotlessly clean and ware is fired on conveyors in as little as 30 minutes.
Stoneware glazes used by Medicine Hat companies were simply mixtures of mineral powders like feldspar, kaolin, quartz, dolomite and chalk. These powders were blended to the desired composition and mixed with water to create a thick slurry. This was then tumbled for many hours in a mill filled with porcelain balls or flint pebbles that ground against each other crushing the glaze particles into finer and finer sizes. The final glaze slurry was a creamy consistency that readily adhered to pottery and melted to form the familiar glassy surface of stoneware.
