I’ve always been fascinated with the art of glassblowing. The craftsmen are so masterful and smooth with their movements while creating beautiful, intricate pieces of art. On a visit to the Corning Museum of Glass, I signed up for an ornament class using glassblowing techniques. Here’s what I learned:
The making of glass has been around since 3500 BC, but glassblowing was invented by the Phoenicians in 50 BC, and little has changed since that time. The process of making raw glass combines different minerals and an extreme amount of heat, but since we’re only concerned with what our finished product will be, I’ll skip that part and move to the Studio where people can take a class or several classes on glassmaking.
Here’s a video explaining what to expect during the class. Because the glassblowers have to move quickly to keep the glass fluid, they don’t have a lot of time to answer questions during the process.
Three different ovens are used for heating and cooling. The first is the” furnace” where you get the blob of glass on the end of a long metal pipe with a hollow core. The raw glass in its liquid form has the consistency of honey or caramel. This furnace is 2500 degrees Fahrenheit. The second at 2300 degrees is called the “glory hole” which is used to reheat the object in between shaping, and the third is the cooling oven called a lehr or annealing oven, usually set at 900 degrees and then slowly the temperature is lowered over many hours to many days.
Different tools are used to shape, stretch or add texture to the glass such as jacks (large tweezers), shears, vises, aluminum molds, and wet paper just to name a few.
Once the glass is gathered at the end, it’s rolled on a steel table to cool the outside and shape it into a sphere. To add color, the glassblower rolls the blob in a tray filled with colored glass pieces called frit. The glassblower then blows a little air into the pipe and covers the blow end with their thumb to trap the air. The heat from the glass expands the air causing a bubble to form and expand the glass. The glass cools quickly to 1000 degrees at room temperature so it must constantly be reheated to keep its fluid form until the shape desired is achieved.
I blew into the pipe to expand the glass.
The heated glass is placed in an aluminum mold to give it ridges.
The pipe is turned constantly to keep its spherical shape. To stretch the glass, the glassblower drops the glass end of the pipe down to the floor and swings it back and forth a few times allowing gravity to do its thing or stretches it with the jacks.
The ornament was reheated about every minute.
When the glass has reached its desired form, the glassblower places it in a pressed wood holder, uses the jacks to cut the glass from the pipe, and gently taps the pipe to disconnect the glass. Now there’s a hole on top of the ornament. The glassblower returns to the first furnace to get another small blob of glass which they drop onto the opening. Then they artfully take the tweezers and stretch a piece up and over to make the final loop to hang the ornament. Here’s a short viseo on how they do it:
Now that it’s finished, it goes into the third oven where the temperature is 900 degrees. The temperature will slowly be brought down over many hours to days depending on the size of the object to avoid thermal stress. Thermal stress is when the glass cracks and sometimes shatters when cooled too quickly.
The Studio offers many different types of glassmaking classes such as fusing, flameworking and sandblasting. It’s fun, it’s safe, and it was one of the highlights of my trip! To see all the classes they offer, visit http://reservations.cmog.org.
And look around. There might be a glassblowing studio near you!
Make Your Own Glass! Open 7 days a week. Book online at http://reservations.cmog.org or call 1-800-732-6845. The Studio is located across the parking lot of the Corning Museum of Glass, 1 Museum Way, Corning, NY 14830. Website: http://www.cmog.org/
*Thank you to Christy for taking some of the pictures while I particpated.