Hot Glass Techniques
2003-01-04 Rev. 2003-06-05, -06-24, -07-02, -09-05, -11-23
2005-02-16, 2006-06-20, -07-22, -08-31, -09-30, 2007-01-31, -04-20, -06-08
[Search on date pattern to find latest changes, more than one may be found.]
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This page shows various pieces of glass created from furnace
glass and discusses possible or actual techniques for making them.
Some of the glass is commercial and therefore the actual
technique may not be known.
2003-06-05 Posted by MF to Yahoo Glass discussion
WORKING ALONE -Picture at right showing my bench and its
third arm.
[benches] The 3rd arm is a freestanding box with a ring into which I dump my hot
punties and pipes, but it also has an adjustable height right angle that is
matched to the arms on my bench. There is a pipe hanger which is a V fold of metal above the
bench.
Transfer goes like this: Chill the jack line, reheat the bottom, hang the
piece, grab a hot punty, gather the bit, marver, blunt and chill the end; lay
the punty down on the middle arm with the bit to the left using the right hand
while grabbing the hanging pipe with the left and pivot it down left to the
piece is to the right. With the right hand, pick up the diamond shears and with
tips, pick up the punty near the bit, sliding it to the right to get it out
beyond the piece; use the left hand to roll the piece, bend over and spot the
center and slide the hot bit into place; adjust the punty to center (you didn't
think I hit center every time did you?); change hands with the shears and take
the punty in the right, squeeze the jack line with the shears (wet or not), test
the punty - I tend to be hot, so it has time to cool, set the jack line on the
arm edge, tap the glass twice with the edge of the shears and whack the
pipe about 6-8" down. When it breaks successfully, set the shears down while
controlling the piece on the punty and if time, grab the pipe and drop it into
the bucket under the 3rd arm. Simple, unh!
ONE GATHER -
I keep working on thinner, etc. People who do pieces with 1 gather have
the following tricks - relatively cool glass in the furnace, a bigger head on
the pipe - some goblet makers use a 1.5" head on a .75" pipe.
If you recall my setup, my yoke has the transfer balls attached in a V cut in a
steel panel which acts as a heat shield very nicely. But it also means that
there is a flat surface on either side of the V, so I can lay
the pipe in the V and roll it easily and lay a hot bit on a punty in one of the
rough notches (it was torch cut when I was learning) on the top and roll it
there. Thus I can reheat piece and punty for another attempt at transferring to
a punty or I can reheat a color or clear gather being used to add a hot bit or
stringer to the piece. With a standard yoke, I have seen solo workers cross the
pipe with the punty, so the punty is laying
on the pipe near the moile. This requires the door be open more or be bigger.
Making: Goblets
Where: CraftWeb discussion
Special Equipment: None
2002-09-21 In a discussion running on
CraftWeb, guys who make goblets say that having the glory hole relatively
cold gives more time for working the piece without the bowl collapsing.
2003-07-02 In another discussion of making goblet feet, several points are
made. Four hours of just making feet on stems on a punty (no bowls) will
insure perfection of whatever method is used. Besides the
wooden footer, and the fancy tool from Emenese,
one person is reported using a small (3x5) thin (1 sheet) newspaper pad with
success. Several people form a gather made on the stem itself, no cookie.
If using a cookie, reheat to the softest that can be handled and really squeeze
it down while turning quickly.
These two sets of pieces were photographed at Elliott's
Hardware, where I work. Each is an example, I think, of the best
that can be produced by low cost, mass production hand made
techniques, unfortunately by low paid people. The colored vases require gathering a small amount of color and gathering a
larger amount of clear, and doing the initial forming. The bubble
in the bottom was almost certainly formed with a simple centered
mold with a blunt spike (because of its size and uniformity.)
Then another gather of clear over the indention to form the
bubble and final forming of the glass. Both of these sets of
pieces have ground tops, which means they are probably not
transferred to a punty and not reheated. The square vases are
clearly mold blown and have no bubble in the bottom. Another vase
like the ones on the left has a round top and four lobed base,
the base being formed by letting the hot glass flow between four
steel pegs.
The pieces on the right were probably made in two sections, the
top being mold blown and then inflated, while the foot and stem
were molded and attached hot. Again, the piece has a ground lip.
It was either annealed on the pipe or cracked off well above the
lip line. 2000-11-06.
Notes on how a team might make bottles
in production situation, written down for woman who was asked to make 12,000
750ml bottle twice a year. on CraftWeb
TRIM THE RIM -
I have been told that one of the most difficult things to do is to thin out the
lip by pulling the lip and trimming if it is too thick. After freeing the piece
from the pipe, the rim may be to thick if jacked in the wrong place or if not
blown out at the jack line. If you heat the lip hot, you can take
tweezers or diamond shears and pull it lengthwise in several places - this will
give you a thinner, ragged edged lip, which you reheat. Then using cutting
shears, you start cutting at the bottom, turning the bottom toward you, so the
peel falls down and away from the glass. If you are quick, it can be done in
one move, but more likely you will feel the glass harden under the shear blades,
so you will turn and cut off the peel, letting it fall to concrete floor or
metal pan and reheat the rim to finish the cut. On the next reheat the cut edge
will smooth and if evenly done, spinning or shaping will be much easier than
fighting with the thick glass. 2007-04-20
Making: Classic bubble on bubble goblet
Artist: Marc Boutte
Where: Divas studio, Ft. Worth, open house demo
Special Equipment: Delicate shears
Marc Boutte working a goblet in the classic
Italian style at Divas Art Glass south of Ft. Worth. Here
we see a late step in making the goblet - placing the bubble that
will form the foot. The steps so far involve creation of a the
first bubble that will be the goblet bowl, just above the pipe
mouth in the picture. Above this is a small blob of solid glass
and a second bubble for the stem, followed by another small knop
of glass. The bubble being applied will be nipped off, heated and
evened and opened to form the foot. All the glass is thin.
The lip is worked by either puntying the goblet or with a goblet
gripper with prongs that hold the foot.
Making: Flat sided pieces
Artist: Various
Where: Various
Special Equipment: Cork Pads, thick with handle, wood
Colin Heaney working a piece of glass
with wood sticks. (His site.) Using wood
to shape glass is a common technique. Wood is most often fruitwood,
notably cherry, soaked until it is waterlogged, so shaping is done with a fair
amount of steam protecting the wood from burning. Cherry wood dowel rods are available from
woodworking supply houses. Besides forcing the glass in to new
shapes from the outside, wood dowels can shape lips inside and
out and a form of jacks takes wood (or paper) fittings. Blocks of
cork are also used for flattening sides or forming a squarish
shape.
The sequence of images of the Marilee Moore demo (below)
starts with a picture of her using cork pads to flatten the piece.
A piece can also be flattened or given multiple sides by letting it sag onto the
marver, lifting and rotating 180, 120, or 90 degrees for 2, 3, or 4 sides, and
laying it down again. 2006-07-22
Steam Stick & Air Cone
"Steam pressure has been used for blowing or
re-inflating a piece on the punty. This is done either by pushing
a wet stick through the narrow opening of the form or by holding
the opening down over a damp surface, a wet board, or a pad of
wet paper.
"Air pressure, from either a simple mouth-blown conical
tool or an air hose, is traditionally used to inflate a form. The
conical end of such a tool fits a variety of openings, and when
it is forcibly held against an opening and air pressure is
applied, the form can be expanded. This process has been used
both to inflate a form that has been broken from the pipe and to
start a piece gathered on a punty. In 1962 Jean Sala gave me a
tool similar to those I later saw used in Murano. Sala’s,
however, had a simple right-angle bend to make it possible for
him to use it alone.
"At Steuben the cone is made of wood and is
on the end of an air hose with a simple finger valve so that the
gaffer or head of the hand shop can use it without aid. There I
saw it used to open out the top of a high bowl. After the piece
was broken off the pipe and warmed in the glory hole, air
pressure was used to open up that thick area of glass near the
rim. Normally, such a form would be slowly opened out with the
jacks and the wall would never be pulled outward from the base.
But the entrapped, expanding air bubble pulled out and thinned
the wall farther and farther toward the base. This is quite a
different action from the stretching outward of the edge with a
jack or even the spinning out of a form with centrifugal force."
"Glassblowing, A Search for Form" by Harvey Littleton
While taking the class in 2003 with Fritz Dreisbach, I learned
that the steam stick or steam cone needs to be rotated with the piece to keep
the seal. Therefore the handle to the steam stick should be small enough
to roll with the fingers. Fritz used a ricer pestle that is smaller than I
was able to find on several shopping trips so I turned one in cherry.
Blocks Wood & Paper
During the 2003 GAS, one studio shaped a large bowl form by putting a pad of wet
newspaper on the floor and lowering the rim onto it, so the steam inside swelled
the walls. It was not turned. MF 2003-07-03
Ring Bubble, RISD Ring
Posted By: Kurt <krw@kurtwalrath.com>
Date: 2/17/2001 - 4:22 p.m.
In Response To: How does he DO that? (Patti)
: http://www.gaiser.org/forums/DCForumID2/552.html #
: Mark Matthews has quite the marble reputation - he's been doing
these bubble things like this one (hopefully the link
: works), also does numbers in them. Any ideas?
You
could make a marble with a trapped bubble down the middle then
use a pair of jacks to neck a line in the middle of your form
until you have squeezed the bubble almost into 2. You should now
have an hourglass shape with the bubble similarly shaped inside.
Heat up the "waist" of the hour glass and use a wet
newspaper to push the inner fold closed. this will trap a ring
shaped bubble around the first bubble.
Reheat and shape into a marble.
This is how I would do this using hot glass techniques and tools,
I'm sure it can be accomplished using similar lampworking tricks.
The neat ring shaped bubble effect is the solid work result of a
glassblowing trick called an "interior fold" or a
"RISD ring". This is the first time I've seen it in a
solid piece and it's pretty cool looking.
I'd like to see a photo of one with the numbers.
Bob Johnson wrote in message <3a992ec2@news.qnet.com>...>Hi
all
> Had this vase in family for many years. It's
hand blown and 25" high.
>Still don't know what type or, from who or, when. Any
info greatly
>appreciated.
>Bob
I turned at first to "Popular
'50's and 60's Glass" by Leslie Pina to cross check, because
I had been surprised at how much some of the commercial glass
echoed what was done in the studio glass movement. On a
closer look at the picture, I would say it could have been made
in any studio from the 60's on. If you can date more
accurately "many years" you might be able to raise its
value by attaching it to a particular artist. I note
that it is easy to make (pull the prongs then remelt to take
off the pull marks) and it appears to be not particularly well
made - lacking proportion and symmetry and being rather top
heavy. Because of its size it might be worth a few hundred.
Depending on whether the inside is all white, and
it does not appear to be, the piece looks to have been made by
picking up several disks of color on the end of a gather of clear
and blowing through them to form the lines of color. After a
further gather of clear over the color, the bottom was pulled,
distorting the color downwards, but giving a clear end to the toe.
The bottom was squared off, perhaps in rod form, and the piece
was transferred to a punty and the top reheated. The top edge was
pulled, perhaps after cutting into lobes, but stretching the
upper color as shown in the center front and left and the rear.
The piece was reheated to round off the pulls and soften the tool
marks, but little effort was made to form the pulls either inward
or outward, to give it a base form. It may simply have been hung
upside down after reheating and left to solidify before being
placed in the annealer. This form would require hot gloves to get
it safely in the annealer, I think. 2000-02-25
Making: Very Large Solid Sculptural Pieces
Artist: Martin Blank
Where: His studio, demo during GAS Conference 2003
Special Equipment: Massive pivoting punty on yoke with large control wheel
Annealing oven with special door to allow piece on punty to extend out under
closed door
Large
shaping block with cross handles brought to work by two people.
The two assemblages of photos below follow the work of
Martin Blank (in brown) and his team making a VERY large solid piece for his
sculpture work. The glass is so big a special punty, clamped to a
yoke, with a large wheel is used for turning. The shaping block is
brought to the glass by two people (second row) and a large oxy-propane
surface mix torch is used for punty heating. When the clamp is released to
extend the shape (row 2, pic. 3), control is tricky. A heat shield guards
the bearings of the yoke. Row 4 shows some finished pieces and the steps in
flattening (with a lifted platform) and final shaping of the piece, with a
pulled tip. The whole unit is inserted in the annealer to even the
temp, with a slot in the door for the punty and when even, the piece is laid
on the floor of the annealer. 2003-06-24 rev. 2006-06-20 |
 |
 |
Making: Large seashell sculpture
Artist: Merrilee Moore
Where: Pratt Institute, Seattle, demo during GAS 2003
Special Equipment: Press made of pipe to form ribs
Mound of wet newspaper to form curve over.
Large cork pads for flattening
Demo by Merrilee Moore at Pratt, GAS 2003, making solid glass shell with special
marver/press shaper and mounded newspaper cone. Prior to the first
picture, the glass was built up in volume and colored with frit laid out on the
marver. The blob was then flattened on the flat marver and reheated prior
to placing it on the hinged grid. 2003-07-03
Making: a large platter with included color, rolled pickup, metal leaf, optic
Artist: James Nowak
Where: His studio, Seattle, demo during GAS 2003
Special Equipment: Shallow color pickup oven, large optic, large marver.
James Nowak making a large platter with included color,
rolled pickup, metal leaf, optic. Note the very shallow kiln (row 2, frame
1) for preheating the roll-up. Among the tools not properly pictured is a
small Hudson-style (pump-up) sprayer with water to soak the very thick paper pad
he uses. The cooling barrel (1,3) is automatic, coming on when the pipe is
laid down. The jacking of the post-optic piece (3,2) is removing the not very
interesting end (2,3 before optic) so the detail runs to the center of the base.
Making: Rollup Vessel
Artist: Team
Where: East Lake Glass, Seattle, demo for GAS 2003
Special Equipment: Kiln, kiln formed glass,
These are shots of a rollup
where a kiln formed sheet is wrapped around a heated billet - glory hole without
furnace.
The murrini technique can produce similar results although it tends to
repetitive design details instead of pictures. Murrini are partly fused in
glory hole, but are always picked up on a glass shape prepared for the purpose
as shown in Powell pictures.
At left the fused panel has been heated in the gloryhole on a kiln shelf, perhaps
overheated as it stuck a bit in spite of the kiln wash. It was not setup
on the kiln shelf and fused in the glory hole, but was fused in a kiln, perhaps
in several steps, I did not ask. In the center, the proper sized gather
has been formed from a block of the same kind of glass (the melted glass in the
studio was incompatible and besides the point of rollup is to add a glory hole
to the kiln but not need a furnace for molten glass.) The
glass of the panel may have gotten a bit stiff during the fighting to get it
unstuck, because the roll is not complete and not successfully stuck all round
to the moile All is not lost, as the edges are worked together in the
last image and progress is made with sticking the rim. I have seen videos
of the process which are smoother than this. 2003-07-02
 |
Making: Eagle sculpture, flower, sword
Artist:
Karen Willenbrink-Johnsen
Where: Houston Studio Glass, special demo
Special Equipment: Garage to park parts
Karen Willenbrink-Johnsen's demo was on
when I arrived "early" and this is a shot near
the end of the completed eagle. The wings, folded on the
back, were made first and garaged, then a textured rock
was made and puntied and the eagle built up on the rock,
with the head shaped at the end with details added with a
torch and stringer. The torch shown in the picture got a
lot of use, it is an oxy-propane torch, being hand held
instead of bench mount. lots of heat. |
| The second demo was done by Jason
Willenbrink- Johnsen, making this cutlass style sword.
The handle was built first then the blade and the two
were merged by heating locally with a torch. The blade
was then further shaped. Because the color of the blade
comes from powder on the outside of the gather, when the
tip was sheared, it showed the clear glass and had to be
pulled and shaped as here, to get the color back to the
tip. |
 |
 |
This sun flower was Karen's second demo.
It was built with a seed pod made by picking up frit. The
petals and green outer leaves were applied as hot bits,
each one being cut off at an angle, then cut in half
lengthwise and shaped. In this picture, more green glass
is being added to form the bud base of the flower (and
later the stem.) Of course, the green glass glows red in
the picture although the greenish colder leaves can be
seen below it. |
Making: Standard hollow ware shape with blocks
Artist: Chris Marrs
Where: His studio in Texas Hot Glass
Special Equipment: Various sized wooden blocks.
These
pictures, taken while Chris Marrs was demonstrating at Texas Hot Glass in
Dallas, show the steps of forming glass including using blocks.
In the top image, the end of a heated pipe has been pressed down
on a chunk of color in the color oven. The remaining layer of glass on the end of
pipe adheres the chunk which is then heated and rolled on the marver to shape.
The color is dark here because of the chilling from the marver. It is
checked for good adhesion.
In the second picture, a gather has been made over the color and
brought to the marver for shaping, moving the glass up off the pipe and around
the color and making it symmetrical.
In the third image, a second gather has been taken from the
furnace and by carrying it pointed somewhat down while turning the glass has
flowed to a cone shape. A block of medium size has been picked from the
bucket of water and is being brought to the glass, the glass being turned
constantly.
Next the glass is being blocked to shape, chilling the surface
for blowing.
And lastly, after another gather the hot piece has been rolled
in mixed colored frit laid out on the marver and a larger block is used to work
the color into the surface. 2003-11-23
Making:
Giant murrini colored bag
Artist: Stephen Powell
Where: Phillabaum Studio, Tucson, AZ, 1997 GAS Conf. demo
Special Equipment: Pipe mold, tall blowing bench, pastorali, large pipe cutting
tool
Special Prep:
Process: Pull brightly colored thick cane with darker outer bands
Slice cane into evenly sized murrini about 1" across and 1/8"
thick
Arrange murrini into rows of similar colors on pastoralli and
preheat on hot plate
Before cylinder of glass is ready, further heat plate in
glory hole and just before rolling, super heat top surface with torch.
After further inflating, finish shaping by blowing down
against V shaped pipes on plate.
Use a pipe cutting tool to remove glass to avoid risks of
cracking off.
Result: a large bag shaped bottle with strong stained glass colors and reminders
of human buttocks and breasts shapes.
Stephen
Rolfe Powell - Blown Glass Process
Stephen Powell picks up the Murrini (cane
slices) that form the stained glass colors in his large blown
bags which calls Johnson. The hot clear glass is about an inch thick. The diameter of
the hot glass was carefully measured to match the length of the
roll up so the edges would meet (if they don't or do it badly, he
makes a different style of piece, I asked at GAS Asheville.) The
plate of murrini is preheated in the glory hole and heavily
torched before the cylinder is applied. [His site showing step by step
technique
http://www.stephenrolfepowell.com/process/process_01.html ]
Near the end of making the piece, it is inflated between two
angled pipes to form the bag shape and set the bottom. The neck
will be cut with a very large pipe cutter.
Reverse Axis or Changed
Axis Vessels
Making:
Artist: Various including
Alex Petrakis glassblowing Reverse Axis and Lino and Starfish
Where:
Special Equipment: None if torch is standard.
Reverse or changed axis vessels provide a way to use techniques which
wrap threads around a piece to provide details which in the final piece run end
to end or otherwise offer variations in patterns that would be much more
difficult to apply.
The basics of the the technique are that a piece is partially blown,
shaped and opticked if necessary and then is threaded placing many fine lines
around the piece in one or more colors. Further work may be done, but the
shape is still a roundish bubble. A hole is then made in the side of
the piece either by heating a spot with a torch and piercing as in the Petrakis
video or by blowing out the hot weakened spot. An alternate spot heating
method normally used before torches were common is to get a blazingly hot bit
and putting the blob of glass down on the piece, thus heating it very locally
and weakening that area so it can be blown out. The bubble or fragments
around the hole are knocked off and the piece reheated so the hole can be evened
up. Meanwhile, a pipe is prepared by doing a small gather and
blowing it out so it is a hollow ring (donut) on the end of the pipe. This
is reheated and flared if necessary to match the size of the hole in the piece.
The piece is necked and the new pipe stuck up firmly on the hole, more firmly
than a punty is normally applied. The first pipe is cracked off and the
piece heated and centered.
What happens next depends on the design goal. Something has to be
done with the rather sloppy pattern around the hole left by the first pipe and
the hole itself. The sloppiness of the pattern may depend on how carefully
the necking to the first pipe was done, thus how much extra glass was left.
The hole is normally worked closed keeping the shape of the piece, but one of
Lino's 'tricks' is to stretch the piece out so the hole is closed in one point
and the circle of threading that was away from the first pipe is at the end of
the other point. 2006-07-22
This page on an Australian site has a long
series of drawings showing how the artist builds up the metal
foil on the hot piece and then puts an image onto the piece Hiroshi
Yamano glass blowing 2002-04-04
Google Video yields a number of video demos under a search of
'glassblowing' and 'glass blowing' including a video from dog
house films of this artist
Glass
Art > Alex Petrakis's Gallery - Glass Artists.org with
Alex Petrakis glassblowing Reverse Axis 2006-07-22
This general site also has a number of other
technique pages, including Graal. Jon
Baskett, computer aided design and decal manufacture
Technical
Database
Afro Celotto
firthm/celotto.htm 2005-02-16
Reticello & other Venetian There is, on this site
East Falls
Glassworks - Glassblowing Demonstrations an extraordinarily good set of
pictures of making a goblet using the reticello technique that results in white
cris-crossing lines in the glass. There is no narration so some knowledge
of what is going on, but every photo will click to enlarge to give a clearer
view. The small images at the top bring out 3 other demos with as many photos
that also enlarge to show making a goblet, a snifter, and a pitcher. 2006-08-31
This demo at Philabaum's Glass web site
Philabaum Glass (click on Glass
Studio link at top, then on Making a Scavo Bowl) shows a nice neat way of
presenting a collection of images of a demo. 2006-09-30
Woven Glass - There are two tricks to
making the appearance of woven (such as plaid) glass, one of which can be done
as warm or hot glass while the other is purely warm glass. The first
is to make a thread pattern murrini by
stacking and fusing thin layers of various colors. This makes one square
of the weave. These sliced murrini are then laid down alternately so the
threads go one way then crossways to that, laying out the plaid or the weave.
This is then fused in the kiln, heated on a
pastorelli, or otherwise heated and
picked up or done as a roll-up. The alternative is
to lay out on a kiln shelf bars of kiln shelf material as wide as a band of
thread which are separated by the same width. Each bar should be twice the
height (or a bit more) of the thickness of the glass. In step one, lengths
of glass either plain or previously fuse ribbon patterns or
stringer threads. These are
taken up to sagging temperature so the section between the bars sags to the kiln
shelf. After cooling, the bars are removed and the strips shifted so the
rise in one is next to the drop in the next. Additional flat strips of
glass are slid in the pattern, over the drop and under the rise. The whole
is then reheated to fuse and flatten the pattern as desired with more or less
texture to "fabric" 2007-06-08
Contact Mike Firth
Making:
Artist:
Where:
Special Equipment:
