HOW TO FIRE A BISCUIT OR GLOST BOTTLE OVEN
This was the basic firing process for a biscuit or glost, updraught or downdraught, bottle oven:
- The bottle oven was filled (placed, or set) with pottery, protected in saggars.
- The entrance doorway, called the wicket, was built up and sealed, forming the clammins.
- The temperature inside the oven was raised to fire the pottery, using coal or oil as the fuel.
- After the peak firing conditions of temperature and 'soak' had been achieved, the oven was allowed to cool.
- The clammins in the wicket was broken down and the fired pottery taken out.
- The whole process would then start all over again.
The process of firing an oven was extremely inefficient. It was wasteful of fuel and other resources. It was also laborious, dangerous and a serious danger to health.
The single most important part the potting process is the biscuit firing. It is here that the pottery body mixed by the potter, according to a recipe, undergoes its greatest test - the ability to withstand ﬁre and to emerge from it the form of sound, useful, practical or beautiful, saleable products.
There's lots more about firing bottle ovens here> on The Potteries Bottle Oven site.