Glass Blowing Class

Today I took a one day glass blowing class at Diablo Metal and Glass in Boston. It wasn't exactly blowing but was Make your own paperweights. We gathered molten glass on a solid rod and spun, colored and shaped it in to those round paperweights you've seen that have cool patterns on the inside.

It was a 6 hour class, though we had time off for lunch. There were four of us in it and one instructor (there was supposed to be an assistant but he didn't show). He showed us how to "gather" molten glass out of the (4000 degree F?) furnace and keep it spinning slowly and how to move it to a bench and shape it with tools.

To make a paper weight you go through a few steps which he showed us in succession. We were manipulating molten glass a few minutes into the class (waste wasn't a problem). First you pull molten glass out of the furnace on a solid pipe. You need to keep it spinning slowly so it doesn't glob off the end. You shape it against a metal table and color the glass by rolling it in pigments in metal trays. The pigments are in forms from fine powders to sand to pebbles. You reheat the glass in another furnace (this one at only 2400 degrees F), and then sit on a bench with two rails that you use to support and roll the pipe while you shape it with tools like tweezers, shears and bowls. You get a swirly pattern you like and then gather another glob of molten glass onto the end to cover it. You shape the glass into a ball and then pinch it so it's on a narrow stem and finally break it off the pipe. After you break off the glasswork you dunk the end of the pipe in water and break off the remaining glass which is waste.

There were a few things that you learned very quickly that I had never thought of before. First molten glass is really hot. Well obviously but there's a lot you have deal with when you're holding something that's at thousands of degrees. First it's really hot just being next to the furnace. Ever put your hand near a fireplace or camp fire? It's a lot hotter. The pipes were about 5 feet long, if you had one hand halfway down it while you're gathering glass from the furnace it's really really uncomfortable, my hand was turning red. The second time you learn to move both hands to the far end of the pipe. Also, just sticking a metal pipe in the furnace for 10 seconds to get the glass, heats the metal very hot. You actually dunk the pipe in a water trough (with the glass sticking out the end) to cool it down before working with it.

You have to keep the glass very very hot to work it. When you take it out of the furance it's like a thick liquid, in less than a minute it will be too hard to work, so you heat it again. While soft enough to mold it glows red hot. As it gets hard to work with it stops glowing, but it's still very very very hot, it just doesn't look it. You learn not to pick up glass on the floor of glass shop with your hands. The glass is so hot we put the "finished" paperweights in a 900 degree F oven to cool! Various kinds of glass have different processes to cool them so they don't crack. Our paperweights will take about 15 hours to cool, in a couple of stages, so I can pick them up tomorrow. While we colored the glass blue and purple and green and other colors, I still don't know what the paperweights look like because when I saw them, they were glowing red hot or the outsides had cooled but the insides were still red.

In the morning we made a couple of small glass spheres and a snowman like shape just to get used to working with the glass. We broke for lunch and then spent about 3 hours making paperweights. I made 4, the last one took about 15 minutes.

At the end of the day 3 guys came into the shop and were blowing vases. It was interesting watching them work together. One was the main guy who sat on the bench, rolled and shaped the glass. Another squated next to this and blew into the pipe, which of course was rolling back and forth (think of a seal blowing musical horns). The third would get additional small blobs of glass and attach them to the main piece so the main guy could shape it. They worked together seemlessly, without needing to speak about what they were doing.

It turns out paperweights are a great introduction to the craft. You can learn to make them quickly and they are very forgiving. If you do something you didn't intend, just heat it again, do something else and it will still look cool. Also, within 15 of the start of the class I was handling molten glass. There were no notes to take, no "what is glass made of" or "these are the stages of cooling glass". I didn't develop the skill to know ahead-of-time how my twists would turn out but I did appreciate seeing the teacher make a glass horse. I could follow how he did it, but I knew I couldn't come close to attempting it. I was dealing with manipulating a big blog! Very cool stuff, I'm looking into other glass classes to take.