What Can I Do With Glass?

Rev. 3/30/95, 8/22/95, 2/11/97, 11/29/97, 1/3/99, 8/19/99, 2/18/2000, 2000-10-29,
... 2003-01-02, -09-27, 2004-01-03, -09-12, 2005-10-23, 2006-03-06, -06-03, -07-08
2008-02-05
Prepared by Mike Firth
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1) A simple list of categories roughly by cost of working the glass
Carved and ground glass - cold worked glass
Foiled and leaded stained (colored) and beveled (usually clear) glass. Flat Glass*
Glass cast in a matrix - Mosaics and dalles and stepping stones
Etched and engraved glass - chemical etching and abrasive blasting. Flat Glass
Glued glass
Kaleidoscopes
Painting and printing, Flat Glass
Kiln worked glass including sagging and fusing, Warm Glass
Kiln casting including pate de verre
Lampworked in a torch, including beadmaking
Tube lampworking, primarily neon and other rare gases and scientific glassblowing
Molten casting - hot glass
Glassblowing from molten glass
Paperweights and marbles

* With the passage of time, grouping of glass activities into categories have changed. In the early 90's when I started, coldworking, stained glass and glassblowing were common terms. By the mid-90's, lampworking, an old term, had come forward again for torch working glass and not long after, warm glass was used in exhibitions for kiln worked glass that had been categorized with stained glass. Now, about '05, a number of schools are using flat glass, lampworking, warm glass and hot shop with some adding cold working for traditional etching and engraving with sand/abrasive blasting included in flat glass.

Brief	Longer
Cold worked	Cold worked Stained, etched, carved, glued
Warm glass	Warm glass Sagging, fusing, kiln casting
Lamp worked	Lamp worked Beads, figures, neon, scientific
Furnace worked	Furnace worked Blown, cast
Books

There are three major groupings of glass working: cold working, warm glass, and hot glass. Most people working with glass end up doing work in more than one area and combining areas has led to some very interesting art.

Cold worked glass begins with using copper foil and solder or solid lead came to frame cut pieces of stained glass and beveled clear and mirror. Besides flat panels, foiled glass can be used to make boxes and lampshades. Glass may be vacuum coated with thin metallic films (dichroic) for special effects. Glass may be laid with cement to form mosaics or thicker pieces (dalles) may be held in cement or epoxy so light shines through. Glass may be cut, carved, ground, and polished with wheels and diamonds to make images or patterns. Optical glass may assembled with special glue to appear to put things inside blocks glass that shouldn't be there (e.g. square bubbles, dichroic films.) Glass may be sandblasted or chemically etched to produce frosted patterns. Stained glass work is the most popular. Sandblasted pieces are often used in buildings. Kaleidoscopes are arrangements of two or three mirrors to form star shaped images; the housing for the mirrors may be stained glass or any other material. Glass is also used as a canvas for painting and as a stone for printing like lithographs.

Warm glass work involves setting up cold glass and heating it in a kiln, also called kiln working. Glass may be arranged in a cold kiln and the temperature raised until the glass flows (sagging or slumping) or melts (fusing); often colors are fused on a flat surface and the result is then sagged into a form. Glass may also be cast by arranging broken glass in various sizes in a mold and heating it until it flows to fill the mold (pate de verre and kiln casting.)

Glassblowing takes two forms, furnace work which is what I do and lampworking or torch work.
Lampworking uses a torch and glass rods and tubes that are held by their cold ends and worked together in a torch flame to make objects or (with a rod mandrel) for making beads, while the glass is hot and dynamic. Torch work can be done in a modest space and you can start and stop quickly.
Torch work is done at two levels, soft and hard glass. Soft glass is harder to work with because it has to be constantly kept hot without melting. If it gets too cool, it cracks. It is most often used for beads, small figures, and goblets. Hard glass (Pyrex) is melts at much higher temps, but it expands and contracts less and thus doesn't crack in ordinary working, but the higher temps make the equipment needed more expensive as an oxygen/propane torch must be used with the cost being about $500 with purchased tanks (less with rented). Soft glass can be worked with a Hot Head torch and MAPP gas spending about $75 to get started.
Bongs and pipes are a specialized part of torch working and there is a lot of disrespect toward them for obvious reasons (obvious to me at least - tobacco isn't good and other stuff used is worse)
A specialized form of torch work is glass knitting which many people have seen at carnivals, boardwalks and malls. Using hard glass, the worker makes hundreds of tiny loops to build delicate ships, birds, and butterflies.
In Neon work, tubing is worked in larger flames to make line shapes which are later pumped to a vacuum to which small amounts of noble gases, such as neon and argon, are added so they glow when electricity is added.
Scientific glassblowing, which is the kind most often found in the Yellow Pages under glassblowing, also uses torches, often several at the same time, and works with Pyrex and quartz to make high temperature glassware.

Hot glass is melted in a furnace. Furnace work involves a lot more prep (hours) before the first glass can be blown or keeping the glass melted all the time, which is costly. From the furnace it may be poured into a mold (casting.) or it taken out very hot on pipes to be blown and shaped. This last is what I do, mostly, and what my site is dedicated to.

3) A longer narrative giving costs, sources of information, etc., in the same order.

In more detail:
Cold Glass
Copper foil technique stained glass work requires only glass, a cutter, special pliers, foil, solder, soldering iron, and a work surface in a well ventilated area. Additional equipment can include forms for lamps, heavy pins, work boards, light boxes, grinders, and more tools, but an investment well under $100 is enough to get started. Copper foil is sold in various widths with adhesive on one side and various colors applied. The glass is cut to shape matching a pattern with a regular gap in between and the foil is applied around each cleaned piece using fingers or a guiding tool to press it in place. Then assembly is done, applying solder to all the foil with a fairly heavy iron, thus making it look like the raise lead came of the other method and making the foil rigid to hold the glass. Foil allows more detail and more intricate shapes such as lamps and using the varying width as a design detail. Foil permits some tricks, like the slice of a nautilus shell applied to a patterned glass that would be much more difficult with came.
Lead came, the older more classic method, is somewhat more expensive if the came is to be pulled, cut, and handled properly but is still only about $100 to start. Lead came is only soldered at the joints not along the length. Lead is more traditional especially with colored windows or beveled glass pieces which are available in standard shapes although they can be hand ground. Stained glass is usually cut from larger sheets, but may be purchased in smaller amounts at many stores around the country.
Many books are available on the topic of making stained glass objects, Library of Congress Cataloguing 748. Lead free solder should be used and work done away from household and cooking surfaces. Periodicals: Glass Artist; Glass Patterns Quarterly goes into detail step by step on a number of different types of projects.

Before or after fabrication glass may be covered with thin metallic films (dichroic) in a vacuum facility to produce an iridescent colors. Dichroic glass may be used like any other glass - foiled, fused. etc. This kind of glass is most often used in smaller pieces, fused jewelry and plates and paperweights. An older use of the term referred to glass that was one color in light passing through it (usually red) and another in light reflecting from it (usually green.)

Mosaics and dalles are a relatively low cost activity that has become much more popular recently. Making stepping stones of glass and cement has increased as molds become available so the craft involves laying bits of glass in a reusable plastic mold that provides an interesting outline. Both involve breaking or chipping small pieces of glass and arranging them to make a picture or color image.
Dalles are thick pieces of glass that are used more like stained glass in a thick opaque frame. The pieces are held by cement (or epoxy), mosaic being more like laying bathroom tile.

Jim Bowman's sandblasted and glued up clock at the West End DART station in Dallas TX

Some of the most unusual pieces made with glass use modern glues. Pieces of window plate glass may be stacked into sculptures with the layers (and green edge) visible. Optically clear glass pieces may be carefully ground and and then glued with special "water-clear" ultraviolet curing glues to appear solid while putting things inside the glass that shouldn't be there (ie. square bubbles, dichroic films, cities.) The assembled pieces may be ground onto spheres. Careful examination still reveals the interfaces as slight changes in the light flow. Silicone and epoxy glues may be used to join unlike glasses and join glass to marble, wood, or metal for special contrasts.

Pieces of glass used in foil or came work can be etched or the etching may be applied to full pieces of glass, including mirror, used like paintings; a major business for architectural partitions. Air pressure blasting can use abrasive or other materials (usually not sand, because of silicosis) and may produce deep looking effects; the least expensive blasting equipment (siphon) providing less control than a pressure pot. Etching can be done with acid pastes, but only a shallow effect. Blasting requires an air compressors, material tanks, ventilation, and protection for lungs (respirator) and surroundings (shielded, filtered room/box.) Silicosis is a risk. Equipment cost is several hundred dollars, most of it in the air compressor which must be fairly large.
The picture at right of a clock by Jim Bowman in Dallas includes internal blasted channels and surface etching of glued stacked window glass with dichroic for the clock face.

Painting and reverse painting on glass take advantage of the thickness of the glass. Glass has also been used like a stone for printing paper similar to lithography, notably by Harvey Littleton in his later years.

Kaleidoscopes are an arrangement of 2 or 3 long slender mirrors inside a more or less decorative shell with something to view at the far end. From a collectors viewpoint, the shell is the most important. Stained glass is a common, easy, shell. A discussion group is at http://groups.yahoo.com/group/kbkb/ signing on to yahoo is required.

Warm Glass
Kiln worked glass is the first step in heated glass (now often called warm glass.) It requires a kiln, which does not have to be as powerful as a ceramics kiln (which can, with care, be used), but is usually bigger (across) and electric. Most kiln worked glass involves fusing pieces of glass at temperatures of 1500-1600ºF and sagging glass at 1200-1400ºF. Often a special pattern of glass will be made up by fusing then the result will be sagged. Equipment required includes glass cutting tools, possibly including a saw, forms for slumping, glass carefully selected for compatibility, a kiln and a ramping controller that will slowly lower the temperature (which is usually not part of a ceramics kiln.) Other costs include a ventilated work space and enough electrical power. Periodical: None known. Book: Boyce Lundstrom's three books on Sagging, Fusing and Casting. Web Site: Brad Walker's http://warmglass.com/

At temperatures just above fusing, casting and Pate de Verre can be done. This requires a heat proof mold. Broken glass pieces, perhaps mixed with binder, carefully placed, can create pictures. Or glass can be stacked above a mold to melt to a uniform mass. The kiln is heated after the glass is placed and raised in temperature until the glass flows or fuses depending on the desired result. The whole mass is then cooled to the annealing point and annealed for many hours, up to days or weeks, because of the mass of the glass and mold together. Periodical: None known

Hot Glass
Hot glass begins with lampworking and at the least costly level with a propane torch using colored and clear rod and tubing with a tungsten or coated metal rod for glass beadmaking. With somewhat more heat (air-propane, oxy-propane, MAPP with air or oxygen) higher melting point glasses (borosilicate, Pyrex) can be used to make more complicated figures and shapes, ranging from the little gossamer swans at carnivals to scientific glass working to goblets and sculptural assemblies. The best torches, called surface-mix bench burners, which are quieter and more flexible, can cost $400-700 and up. When thicker pieces are made, an annealer is required, which may be a kiln or home built, costing $200 and up. Scientific glass work is lampworking and most glassblowers listed in the Yellow Pages do this. Besides the materials, including fuel, eye protection and ventilation are needed; some glass colors contain lead. Periodical: Glass Line. Source: Wale Apparatus & Arrow Springs Best Book: Contemporary Lampworking Periodical: Flow
Neon tube working is special category of lampworking which requires special burners to make the long sweeping curves. Carrying out the entire process to make a glowing neon sign or object requires very expensive equipment to produce high voltages and vacuums and clean out the tubing; since neon sign workers have this equipment getting friendly with one may save the expense of buying it. Best Source: The Neon Museum and The Museum of Neon Art websites.
Scientific Lampworking works with Pyrex-type and fused quartz glass to make heat resistant equipment for laboratories and solid state research and industry. Large torches and replacements for the hands to revolve and fit large glass tubing together (called glass lathes) are part of the operations as well as skills such as drawing a bubble back in to make a double walled vacuum bottle for holding very cold liquid gasses. The American Scientific Glassblowers Society

More Hot Glass
The fastest actions occur with off-hand glassblowing, where glass is melted and gathered in a molten state on a hollow pipe so air can inflate the gather for shaping. Further glass may be gathered on the outside, color bits may be picked up, glass details may be formed, etc., until the piece is done and is placed in an annealer to hold and then cool. The very high temperatures involved and the extended heating time require care in setting up facilities and often will require special zoning in places that have it. It is possible to melt glass for working for under $1,000 but double that is more realistic and double that ($4000-10K) likely for a minimal professional setup. Tools that stand the heat are limited production and costly ($100-200 each.)

Molten glass casting is also done from a furnace where the glass is scooped out and poured into a heated mold, which is then annealed. Because of the thickness of the glass and mold, the annealing times can easily run to days of slowly lowering the temperature. Some of the most complicated glass pieces seen today are cast from several different colored glasses, producing shaded effects. Periodical: None known

Paperweights are made with a combination of skills, although they can be made entirely on the pipe or its solid relative, the punty. Classic paperweights require much preparation which may include flame working to make millefiori rod or animal or plant figures which are encased in clear molten glass to make the final piece. Modern style abstract glass forms and bubbles are less complicated to make. Paperweights require an extended annealing time that can take days if large.

Marbles may be made by lampworking or off hand techniques requiring special tools (primarily graphite pads with hemispheric holes) to make totally round objects.

Best Books (Also, you might look at my longer bibliography page)
The best book on furnace glassblowing around right now for beginners is Beginning Glassblowing (previously called Ed's Big Handbook of Glassblowing) by Edward T. Schmid, available from him ($27 with shipping, Edward T. Schmid, 927 Yew St., Bellingham WA 98226) or from the Book Exchange [90 W. Market St. Corning NY 14830 607-936-8536 FAX 607-936-2465] It includes good drawings, lots of suggestions, etc. His "Advanced Glassworking Techniques" also very good. I got my copy and read about 30 of the 320 pages of material and the blowing time for the things I want to do from the book passed the 1,000 hour mark.
Edward T. Schmid Glass Mountain Press, 927 Yew Street, Bellingham, WA 98226 $32.95 + $4 for priority mail, 320 pages, ISBN 0-9638728-1-8

A GLASSBLOWER'S COMPANION - Dudley Giberson [Joppa Glassworks, Inc., P.O. Box 202, Warner NH 03278 603-456-3569 FAX 603-456-2138, e-mail joppaglass@conknet.com] announces via post card his completion of A Glassbower's Companion, ready to ship in mid-December, 136 pages 300 illustrations, $39 including shipping.
Having gotten my copy, I am impressed by the book. This book is primarily an equipment book with excursions into the history of working glass and how it might have been done down through the centuries. If I had to position it with respect to Henry Halem's book, Glass Notes, I would say that while Henry has a bias toward big expensive equipment and offers a lot of casting information, Dudley has a bias toward buildable equipment and offers many hints on bead making. For a person starting to build equipment, I would say that Dudley's book is more useful. The content of the book includes 5 glory holes, 10 glass melting furnaces, 5 annealers and 5 accessories involving heating. Each of the first three groups includes items that are more useful for theory, philosophy or history than for construction. There are a lot of well done computer assisted drawings.
The best book on building larger equipment is the 3rd Edition (not earlier ones) of Henry Halem's Glass Notes, $30 per book plus $4 s&h for the first book, $2 for each additional. Make checks to Franklin Mills Press [P.O.Box 906, Kent OH 44240, 330-673-8632, FAX 330-677-2488, hhalem@glassnotes.com] and MasterCard or Visa may be used.
The best book on lampworking is Contemporary Lampworking by Bandu Scott Dunham [Salusa Glassworks, P.O.Box 2354, Prescott AZ 86302 $35.95 (add $2 only if want Priority Mail shipping). 272 pages, ISBN 0-934252-56-4] This book is first of all a great pleasure just to handle and look at. It is in landscape (horizontal) format with a glossy hard cover and soft sheathed wire bound binding with several color pictures. Virtually every page has pictures and drawings. Photos include work by a wide variety of artists. The instructional drawings are precise and contain only enough lines to give detailed information.
Flow magazine http://www.theflowmagazine.com/ offers working suggestions and interesting information about flameworking.

The best books on fusing are those by Lundstrom available at many libraries. "I'll "ditto" Kathy Cowan's advice - Boyce Lundstrom's "Glass Fusing Book One" is the very best! I have most every book ever published on fusing, and his is the easiest to understand and the most comprehensive." AVERY H. ANDERSON CompuServe. Boyce Lundstrom wrote three wonderful books that deal with fusing, slumping and casting. .. Kiln Firing Glass (Glass Fusing Book I) .. Advanced Fusing Techniques (Book II) .. Glass Casting and Moldmaking (Book III)
If you're just doing fusing and slumping, Books I and II are probably what you're looking for. All three are available from Chester Book Co., 4 Maple Street, Chester, CT 06412 (1-800-858-8515). and many other sources. 12/10/95 Also contact Bullseye Glass [3722 SE 21st Ave., Portland OR 97202] which sells glass tested compatible for fusing.

Many community colleges offer continuing education classes at very reasonable cost on making stained glass objects.

My new (2000-3-6) nominee for best book on all aspects of glass working is the 1998 book by glass artist Lucartha Kohler, Glass, An Artist's Medium, [ISBN:0-87431-604-x, Krause Publications, 700 E. State St., Iola WI 54990-0001, orders 1-800-258-0929, 715-445-2214; Dallas Public Lib. CFA 748.2 K79g]. Because Kohler has worked in many of the variations of glass that she is writing about, she gives excellent coverage of almost every aspect of glass working (except furnace glass where casting gets more coverage than blowing and that not much.) More importantly, she seems to give enough information about doing stuff, like glass painting or kiln working or cold working that a person can understand how to do it. This is not an elementary exercise book and it is not a complete coverage of all aspects of glass; it is a good coverage of some aspects of many ways of working with glass with particular attention to kiln worked and cast glass which she has done a lot of. A good list of sources, a glossary, and notes on Safety.

The best overall book on a wide variety of glass working activities is probably The Complete Book of Creative Glass Art, by Polly Rothenberg, 1974, which is apparently not in print, but which is available in many libraries and thus by interlibrary loan to all. "500 Photographs Apparently superb introduction to most aspects of doing things with glass; the parts I know are dead accurate. Includes photos, sample projects with all steps. Leaded stained glass, Bonded glass (epoxy), Fired glass, Painting glass, Glass jewelry, Blown Glass, Glass Sculpture & Architectural Art." Mike Firth

Glass is a material made from silicon oxide (quartz, sand, etc.) made easier to melt with chemicals including limestone, soda, and potash. When cold and broken, the pieces are usually very heavy and very sharp. Obsidian, a volcanic glass, was used to make sharp weapons and tools by stone age peoples around the world. Yet if heated glass is sharply cooled by a heavy long blast of cold air it becomes extra tough tempered glass, but if that toughness is scratched or nicked, the shattered pieces are round edged chunks that can be rolled in the hands, as can be seen after many automobile accidents in the remains of side and rear windows. (Front windows on cars have a layer of plastic to keep people from going through.)

The properties of glass vary with the formula which can be tuned for different results, just as cast iron is different from cast steel is different from stainless steel. As a midpoint figure, we might take the specific gravity to be 2.4 so a cubic foot weighs about 150 pounds. Unlike many materials which melt at a specific temp, like ice at 32°F (0°C) or lead at 621°F (327°C), glass is squishy to liquid over a long range of temps. Art glass for example is commonly worked as a thick liquid at 2050°F while it is soft enough to sag slowly under its own weight at about 1000°F.

Glass does not easily blend when two colors are heated and melted together. This allows a glassworker to make pictures by aligning rods of various colors and then reducing the picture size by pulling the glass. Yet a thin layer of clear colored glass, applied to the inside of a thick layer of clear glass can make the whole piece take on the color.

Like all materials, glass changes size with heating and cooling. Unlike many other materials where related materials (say kinds of steel) behave similarly, different formulas and colors of glass may expand and contract differently. The measure is the COE - Coefficient of Expansion. Because glass is brittle when at room temp, differences in COE at hot temps can introduce strain that will crack the glass.

Unlike most materials in which changes in the heating and cooling schedule may produce various results (changes in grain size and hardness in steel.) but do no harm, with the exception of tempered glass, glass must always be cooled under controlled conditions, annealing to keep strain in the glass as low as possible. Glass normally has to be cooled over several hours, longer for thicker glass, over the range from the annealing point, about 900F (13 dPas viscosity) to the strain point (about 600F for art glass, 14.5 dPas.) Faster cooling results in broken glass, the sound of breaking glass being common in studios as pipes are set aside in bins with fragments of glass attached. 2003-01-11

[In answering an newsgroup query, it occurred to me to add some notes on uses of glass that fall in the categories discussed above, but from the opposite point of view, not doing them, but buying them.]

From: "Mike Firth"
To: <below>
Subject: Re: beginning blower
Date: Saturday, January 19, 2002 10:41 PM

Well, how can I judge talent at this distance and without seeing any work?
In addition, I am a person who recognizes that color is very popular in blown work, but I don't much like color in my glass work, so I am bucking the wave/trend, whatever.
I don't see any problem with your age or gender - I was about 50 when I started doing this stuff. If you are in New Orleans and stay hooked to people who do this it will be a lot easier than setting up on your own, but I am person who finds it easier to do it myself than to push myself on people, so I don't follow my own advice.
It is easier if you are serious to either get access to or make your own equipment so that you can blow for several days in a row. If you do it like I do, with a day or afternoon of blowing every few weeks, you spend a chunk of each session getting back into the skills and rhythm. Several days in a row, you keep the basics flowing. It costs more to set up for the several days in a row - safety, temp holding overnight, etc.
I blow mostly for the physical act of blowing and find that I am mentally tense before and more comfortable afterward when I do it. Perhaps that's why people call it an addiction!
I have also found that the pieces I like a lot, some people like and others don't, but often the pieces I think are just okay (ornaments I give away) are beloved by people who get them - handmade and unique and all that - and I find them in windows, on shelves and in trees several years after I gave them.
If you finish the class and want to keep on going, why not?

Mike Firth
Furnace Glass Web Site/Hot Glass Bits
http://users.ticnet.com/mikefirth/start.htm

----- Original Message -----
From:
To: mikefirth
Sent: Saturday, January 19, 2002 4:33 PM
Subject: beginning blower

Mike,
love your site....I have a quick question.....I am 40...female and the mother of a 10 month old...I just started taking a glassblowing class at a studio here in New Orleans...I'm hooked......is it at all possible that I might have enough skill do something with this.
Not earn a living, but create some pieces that have artistic value....even if just for me.

appreciate anything you can offer in way of advice
Kay Toca-Adamo

Because this is my site about furnace glassblowing, here are two detailed descriptions.
A Narrative about the steps of blowing glass.	A Visit to a studio as a place.

What Can I Do With Glass? What will it cost?

What Can I Do With Glass?
What will it cost?