Glass Blowing

What Is Glass Blowing?

The glass blowing art begins by heating glass in a furnace until it is soft and pliable. Next, the glass blower dips the end of a blowpipe into the molten glass, gathering a blob of glass on the end of the pipe. The artist then rolls the soft glass on a marble or steel table, which begins to shape the piece and also to cools it slightly, to a temperature where it will not drip. The artist then begins slowly blowing air into the blowpipe, creating a bubble. More glass is added, and the artist continues to blow and shape the piece, using a variety of tools and sometimes molds to create the desired effect. If the artist wishes to add color, the hot glass is dipped into crushed colored glass before blowing.

After the piece has reached it's desired shape and is complete, the process of annealing begins. In this crucial final step, the piece is slowly cooled so that it doesn't crack and break.

Glassblowing Techniques
The batch of glass is mixed and ready to go. Glancing around the glassblower's workshop (called a hot shop), we see a number of tools and equipment that'll soon be in use.
First is the initial furnace, inside of which is a pot (sometimes called a crucible). In a process called charging, the furnace is filled with large amounts of batch that melt at temperatures higher than 2,000 degrees Fahrenheit (about 1,100 degrees Celsius).
While glassblowing can be done individually, it's so challenging that it's often done by a team. When things start to really get underway, the lead glassblower, called the gaffer, reaches for his blowpipe, which is usually made of iron or steel and measures about 4 feet (1.2 meters) long. The blowpipe is dipped into the furnace and comes out with a gob of molten glass on the end. After the glass is secured, the other end of the pipe is cooled off in a barrel of water.
Once the gaffer is ready, he'll blow through the tube and start to create a growing bubble in the glass. Whenever not blowing, the end of the tube is capped so the hot air remains in the glass and helps it retain its shape. More layers of glass can be gathered and added with a gathering iron, or by dipping the glass attached to the blowpipe back in the batch.

Glassblowers often make use of a large, flat surface called a marver to roll and shape the glass. Several tools are also used while working the glass. A block is a wetted wooden shaping tool, as is a bladed tool called a jack. Heat shields and paddles are often employed to shield the blower from extreme heat. The paddles can also double as a tools to smooth out hot glass. Tweezers are another tool useful for grabbing and manipulating pieces of hot glass.

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