So I Spent a Day Glassblowing
Glassblowing is another one of those things that has aways fascinated
me. I can remember going to the Corning glass works and seeing
glassblowers, the syrupy molten glass, the glowing opening of the glory
hole, the graceful fragile results. It definitly left an impression. In
highschool we melted lime glass in a bunsun burner. We pulled out
capilary tubes, made an eye dropper, perforned a right angle bend. My
sister sealed the end of a piece of tubing, and used that to blow a
tiny bubble, perhaps 1" in diameter, and as thin as paper.
I accedently brushed the tip of my finger against some very hot glass,
and could feel a little bubbling sensation as the top layer of skin
turned to steam. It didn't leave a visible scar, but I still remember
that feeling. I eventually got a book on "glassblowing" that
mostly focused on lamp work (working glass in a torch flame as apposed
to using a large melting furnace.) The author provided a number of
projects some utilitarian, some decorative: The mercury diffusion pump,
the swizzel stick with a glass snowman at the top. The contrast between
the two was starteling.
Two
weekends ago a glass studio here in Mountain View was having an open
studio. I went. They had lots of artists show their wares, but the
thing that really intersted me were the people demonstrating making
lampwork beeds, and a man doing full sized glass blowing. I was hoping
that perhaps the furnace Mark and I had built for foundry work could
also be used for glassblowing. I poked around and asked a lot of
questions, but the most important thing that I did was sign up for a
glassblowing class the following weekend.
Dave (who was demonstrating) teaches the class, and there are only two
students. The class is on both Saturday and Sunday from 11am to 4pm. In
that time you get quite a bit of time actually working with the glass.
I was surprised at the two student limit, but having taken the class
I'm now under the impression that having more then two students around
dealing with hot glass on the end of a long stick in cramped quarters
would almost certainly end in dessaster.
Here in the picture you can see out instructor Dave heating a vase in
the glory hole.
The other student's name was Gail, and here's a picture of the three of us.
The first exercise we did was to use a punty (which is just a metal rod
maybe 1/2 or 3/8 in diameter) to dip glass out of the glassfurnace and
attempt to make a teardrop shaped piece of glass by alowing the glass
to drip off the end, without letting it fall all the way off. This is
to help you get a feel for the glass. Gail and I produced a number of
drips, many other drips got away from us and ended up as splats on the
ground. Here's a picture of the
glassblowing area. In the foreground you can see the large squirl
cage blower that we used to keep us cool. Gail is at the Marving plate
near the center, and the glassfurnace, and the glorry hole are to the
left.
After doing the drips, we headed right into making our first
paperweight. A glass paperweight is made by dipping a blow pipe into
the glassfurnace to gather up a glob of
glass. You can then work the glass into a cylinder shape (called
Marving) by roling the glob back and forth across the surface of the Marving Plate (which is just a metal plate
at a convienent height for roling out the glass.) In the photo the
marving would be done over on that clear area to the right, and then
colors could be added to the glass by dipping the glass into the piles
of colored frit on the left. The frit is just colored glass broken up
into little crumbs. After roling the glass in the frit you put it back
into the furnace to melt the frit.
Most
of the shaping of the glass is done at the bench. The bench is a seat
with two rails to support the blow pipe as you role it back and forth.
This roling action is important in order to keep the molten glass
centered on the end of your pipe. You can then work the glass with
various tools. The bucket contains a number of wooden blocks which are
made of fruit wood, and are used whet to shape the glass. The big tong
like tools are called Jacks, and they're used to narow or "neck
down" the glass. There are two kinds of jacks shown here the ones
to the left are the Round Jacks, and the ones to the right are the Flat
Jacks. The gray blocks with the hemisphereical dents in them are
graphite blocks used to shape marbles. The ice pick, is used to push
indentations into the surface of the glass, or to pull features along
the surface of the glass. The file is used to score the glass before
tapping it of the end of the pipe. There are also some shears used to
cut the hot glass.
An important skill to learn when working the glass is to be able to go
from the furnace to the bench whilst keeping your glass on center. This
can be quite tricky since you have to back up and sit down all the time
turning and keeping an eye on the glass.
Well here's a list of pictures. I'll flesh out this page later...
