Centering Glass for Glassblowing

Video Transcript

" Hi! I’m Jim McKelvey with Third Degree Glass Factory in St. Louis. You can check us out on the web at www.stlglass.com. Today, we’re going to learn about glassblowing for expertvillage.com. Now, as I’m turning in the glory hole, I’m only rotating the glass as fast it needs to go to keep it on center. You’ll see a lot of beginners…I’m going to do this wrong…will turn the glass like that. They just sort of mindlessly spin it. You really want to turn the glass only as fast as it wants to balance. You want to balance it, if you’re turning in a clockwise position, at about let’s say 11 o’clock. And if you’re turning counterclockwise,…I’ll turn counterclockwise here...you want that bubble to balance right about 1 o’clock. If you switch back and forth, you can go from 1 o’clock to 11 o’clock back to 1 o’clock. You’ll notice that as the glass heats up, I have to spin more quickly. This is one of the things about controlling a bubble of glass. The rate in which you rotate the glass is always going to be dependent on the heat and mass of the glass. So the hotter the glass is, the faster you’re going to have to turn it. That’s one good way to judge the heat of the piece, because you can’t really see in the glory hole how hot it is, but you can tell how hot it is by how fast you have to turn that pipe. So, now I’m starting to have to turn the pipe a little bit faster, which indicates to me that I’ve got a nice hot bubble. We can come out and shape it on the marver now. "