slumping

slumping is a technique in which items are made in a kiln by means of shaping glass at high temperatures. Slumping glass is a highly technical operation that is subject to many variations, both controlled and uncontrolled. When an item is being slumped in a kiln, the mold or surface over which it is being formed,(which can be made of either ceramic, sand or metal) must be coated with a release agent that will stop the molten glass from sticking to the mold.

this is what i am doing and have documented for you.

this is the cylinder as it is being loaded into the kiln at room temperature.

it is heated up slowly to 580 degrees celcius. the cylinder is held at this temperature for an hour. during this hour the heat in the sides of the cylinder builds up and it slowly starts to move outwards.

it slumps and gradually opens over the hour.

 

it gets lower and closer to the kiln shelf that it is resting on. 

 

for such a simple process much can go wrong. you need to take into account the thickness of the glass, the colour, where the elements are located in the kiln, and how long it stays at the temperatures. 

this is the final product, cylinder sheet glass. info about this process and its history can be found here. 

from here it gets slowly cooled to room temperature and then i use it to make my art.