Back to Ganoksin | FAQ | Contact

Glass cookies


#1

I was wondering if anyone here has ever done the sort of glass work
where a cookie (british equivalant is biscuit) of glass is poured then
stamped with a steel cutout of a fish, starfish, cat, or other design,
then a hole punched with a steel wire so that it can be used as a
pendant. A variation is the design is cut out of thicker steel and a
mold welded up which makes a 3-d fish, flower, et cetera. then the
glass poured into the mold.

I have many questions: What is the pouring temp and stamping temp?
Must the steel be stainless? If stainless how is it cut? Must kiln
wash be used on the supporting shelf? Can the wires for pendant holes
be welded to the support sheet instead of punched from the top? For
the molds must surface detail still be stamped? Are there any U.S.
schools for learning this? (I don’t have the money to go to Venice,
Israel or Czechoslovakia to study.)

Thanks, Geo.


#2

Hi George… Often the “cutout”, is a lead stamp on the end of a short
puntille,(rod). You can make the design yourself, as lead is easily
melted and cast. The temperature of the glass is determined as much
by its visual liquidity, as by an actual temperature taken. A glass
crucible as well as a lot of other tools are necessary for this
seemingly simple operation…and, it usually takes two people.
Cullet, (broken chunks of raw clean glass) is heated to a liquid
state in the crucible. A small amount of the liquid glass is then
"gathered" on the end of a a long steel rod called a “puntille”, or
"punty". A small amount of that glass is then dripped on a thick, flat
steel table used for cooling and working blown glass, called a
"marver". The “cookie”, or wafer of glass is quickly stamped with the
cast stamp, and a hole is quickly poked through the top with a small
thick awl, or the tip of a pair of steel glass pincers used in “hot
work”. For finishing, , the still hot piece is flipped over, picked up
on the back on the end of a punty with a small bit of hot glass used
to stick the piece to the rod, and then smoothed and finished by
quickly sticking it in and out of a gas heated “glory hole”,
(basically, a large tube sealed at the back, with a door at the front
with flames coming out of it…the door has a hole in it to fit pieces
through and yet retain the interior heat). Or alternately smoothed
while on the puntille (or on the marver) with an acetylene torch. The
finished piece is then removed from the punty by touching a steel
glassworking tool…usually “jacks”, (very large expensive flat sided
steel tweezer-like tools…when you’re pinching and pulling hot glass
on a rod, its called, “jacking”…yes…that’s where that phrase comes
from…sigh…)that have been dipped in a bit of water to the spot
that joins the piece to the rod. The water cools just that spot so
that a small rap on it separates the piece from the rod. This is
caught by someone else, and placed in a “Lehr”, (glassworking kiln),
that has kiln-washed shelves, or placed in there on pieces of
fiber-frax to keep from marking the more delicate work. The finished
glass pieces are then annealed overnight so that the glass temperature
attains the same temperature throughout the piece, and is brought down
to room temperature at a gradual rate, so as to prevent exploding that
will inevitably occur if the glass cools too rapidly or unevenly.
Pieces made with this method are usually a bit large. Smaller than
say…3" across is too difficult to make by this method. These pieces
are mostly ornaments. Alternate method, is to pour the liquid glass
into a mold…I’ve used cast Iron muffin pans before. Available in
fish shapes as well as many others, but these are large, and not
suitable for jewelry. For tiny jewelry work, you’d have to do “lamp
work” Which involves heating glass tubes over a steady flame, and
manipulating the glass. Any number of minuscule things can be made by
this method. The only other thing I can think of is “pate de verre”,
where ground colored glass is placed into a mold, and then melted and
annealed in one step in a glass kiln. Colors are obtained either by
coloring one batch of glass at a time by using colored minerals such
as cobalt, (blue), that are added to the hot glass, or by using
expensive gorgeous rods of colored glass that are usually made in
Germany. But that’s another story. Trouble with glass, is that it
usually involves lots of expensive, specific equipment. Check around
to see if any of your local colleges universities or trade schools
have a working studio where you can sign up for a course, and
surreptitiously produce what you want while attempting to meet the
course requirements :slight_smile: That’s what many glass beginners do here. Hope
that this helped a bit, and wasn’t merely more confusing. Best wishes,
Lisa(yeah…yeah…I used to blow glass too, but as you can see from
the terminology, its a mostly masculine genre…lol…) Topanga, CA USA


#3

Using simple lampworking tools you could easily create these types of
items. I have a propane/oxygen torch specifically built for this type
of operation. You could then either find or make your own graphite
stamp by carving it with simple tools. In this case you would not pour
the glass but form the glass into the shape you want. Then once you
have it how you want it to be stamp the impression into it. Then you
set it into the kiln, with or without kilnwash on it (since the glass
is not flowing it will not stick). I use two types of glass, Itailian
and Czech, both become flowing at 1,100 to 1,200 approx, they are not
tacky anymore at 1000. I make holes with a variety of tools, the
tunsign (sic) pick will do it fine. It doesn’t like glass thus it
doesn’t stick. Also if you don’t want a stamp you could always draw
your figure on the glass with thin rods of a contrasting color. I
never have taken a class and I successfully sell my work to people all
over the world. I learned from books and videos, but mostly without
any instruction at all, just some effort. It is easy, fun and
interesting. Truely. Not expensive at all, and a great fun activity.
Most of my tools I made, the only expense was my torch (150.00) and my
glass (about 100.00 to start, I have about 400.00 worth though, I love
my glass). Other than that, an oxygen tank (the bigger the better) and
a small barbeque propane tank. I cannot think of anything else needed
(oh a kiln of some sort)

Good luck!
Thank you so much

Laura