To become an expert glass blower, you will need a good teacher and a great deal of practice. The actual process occurs when molten glass is inflated into a bubble, by the use of a blowpipe or a blow tube.
The temperature required to heat glass to be blown is roughly 2,400 Fahrenheit. This will heat glass to the point where it will appear almost white hot. The bubble is allowed to rise, and then the temperature is reduced to about 2,000 degrees F. The glass will now appear orange.
Glass blowers use three furnaces, according to the Hebivore Hippi. Each furnace serves a different purpose. The original furnace holds molten glass. The second reheats a glass piece. The third is used to cool the glass. The cooling step may take from hours to days, depending on the size of the piece. This allows the glass to cool without risk of thermal stress cracking it.
To begin the process of glass blowing, a blowpipe is preheated and dipped into molten glass. Then the glass will be rolled onto a thick, flat sheet of steel known as a marver. This step will allow a cool skin to form. The bubble is created by simply blowing air into the pipe.
Free-blowing glass involves blowing air puffs into the blowpipe. Then a skilled glass worker can inflate the glass and work it into the shape that is desired. Almost any shape can be made this way by swinging the pipe while air is blown through it.
Mold-blowing is an alternative process that uses a glob of molten glass placed at the blowpipe’s bottom. It is inflated to fill a mold made from wood or metal. The design will result from the mold, not the mind of the glassblower.