The Art and Craft of Glass Blowing

sand-melt-glass

First, the batch of melted sand mix is charged in crucible like furnace at above 2,000 degrees Fahrenheit (1,100 degrees Celsius). Then the glassblower, called the gaffer, uses an iron or steel blowpipe about 4 feet (1.2 meters) long. It is dipped into the crucible and comes out with a gob of molten hot yellow glass on the end. After the glass is secured, the other end of the pipe is cooled off in a barrel of water then the gaffer blows in the pipe to create a glass big bubble. This process may be repeated several times.

During this process, the partially blown glass, or the parison, is turned around and around and bits of glass are often added with the use of a smaller metal rod called a punty. It is often that glass cools to the point where it is unworkable, That is when second furnace called a glory hole is used. This allows formed glass to be held suspended from the end of the rotating blowpipe and rest on metal stands, called yokes, until it’s hot enough to continue.

glass-bubble

The glass bubble is then put on a flat surface called a marver and is rolled and shaped. While this is going on, a metal rod called a pontil is attached to the base of the blown glass to hold it while the mouth end is being shaped.

Once the glass is shaped and ready it is time to cool it properly with one more furnace called an annealer. Since glass may naturally crystallize it is important that the glass retain its scattered but rigid molecular structure as it cools or it will become unstable. The annealer helps control that process by controlling the temperature.

Lastly, after the extended period of time cooling in the annealer, the glass is taken to the cold shop where it can be ground, polished, engraved, enameled and otherwise detailed.