The main ingredient is known in the trade as ‘batch’ which consists of a mixture of cullet, litharge powder, potassium carbonate and white silica sand.
They are mixed thoroughly together and placed into the furnace pot, the temperature at this point is 1400c and it takes upto 36 hours for the mixture to melt or found, hence the process is known as founding. The founding is then known as metal and to work with the metal the furnace must be set at 1200c.
Three men work at each furnace and they are the Servitors, the Glass Blowers and the Bit Gatherers. During the manufacturing process the glass temperature will be reduced to approximately 720C.
The worked glass is then transferred into a tool known as the muffle which operates at 500C until this stage of the process is completed. The muffle is then set to a descending temperature overnight over a 12 hour period to cool the glass.
When the glass is removed the next morning it will be taken to the process area where the glass will be scored to remove the top of the glass in a process known as ‘cracking off’.
The glass will then be bevelled on a diamond impregnated wheel to smooth the glass before going to the glass decorator to have the relevant patterns cut.
After being cut each glass is acid polished, a process where it will be subjected to a mixture of hydrofluoric and sulphuric acid which is a 2 minute process which gives the crystal a polish.
The glass is now ready to be boxed and distributed to customers world wide.