Essentials to know before taking up glass blowing

Glassblowing - it's the blowing (inflating) of a molten glass blob into a bubble or parison by a tube. The origins of this art can be traced all the way back to the Mesopotamian civilisation even though the art flourishes even up till today in the modern era. This article serves as a guide to introduce the art of glassblowing and how it works.

A major tool in glassblowing is the blow tube/pipe. This tube is dipped into a molten glass containing furnace, following which, the glass is gathered onto the tube tip. After that, rolling of the molten glass onto marble slabs or thick steel sheets takes place (this surface is referred to as marver). This makes a cool skin on the glass.

Next up is the actual blowing process wherein a substantial amount of air gets blown into the molten glass material through a tube to create a bubble which is shaped using blocks. Many jacks may also be employed to make a shape onto the glass. The glass ha s tendency to get cooled during this process and is therefore inserted into the 'glory hole' which is another furnace for reheating.

Then, using a paddle, the bottom is flattened. During this part of the process, colouring and decoration may be done by the addition of canes or coloured glass patterns into the glass.

Finally, to cool and set the glass, it is placed in an 'Annealer' which is another furnace. This part of the process takes anything between a few hours to many days - this depends (primarily) on the size of the piece.

Temperature plays a crucial role in glass blowing. The raw materials transform into glass at about 1315°C. At this stage, the glass is almost white hot. The bubbles are then allowed to rise out of the glass mass ('fining out'), after which, working temperature is brought down to about 1100°C (the glass is bright orange at this stage). Most glassblowing is carried out between 870-1040°C however; Soda-lime glass is rather plastic and quite workable even at temperatures as low as 730°C. Annealing is mostly carried out at 430-480°C.

This may sound easy but given that the entire process is done by hand, it takes considerable experience before one churns out brilliant pieces. Don't worry though; even the road to perfecting this art is an eventful one since every piece on the way is unique.