Glossary G

GAFFER — The master craftsman in charge of a chair, or team,of hot-glass workers and the entire production of a project.

GARAGE —  A heating chamber used to hold and keep hot parts of objects that are intended to be assembled on the blowpipe while other parts are being made.

GATHER -– The technique of winding a ball of molten glass (called a gather) from the furnace onto the end of a blow pipe or punty.

GATHERING IRON — A long, thin rod used to gather molten glass.

GLASS —  A homogeneous material with a random, liquid (non-crystalline) molecular structure. The process requires that the raw materials (batch) be heated to a temperature high enough to produce a completely fused melt. The glass, when cooled rapidly, then becomes rigid without crystallizing.

GLASS CASTING — When you heat glass until it melts, and then it is poured into a mold.

GLASS CLAY — Glass powder that is mixed with a binder and water to product clay.

GLASS CLEANER —  An ammonia-free glass cleaning product, soap and water or vinegar.

GLASS CUTTER —  Used to score (scratch) the glass. See cutter above.

GLASS KILN —  Unlike most pottery kilns, glass kilns have heating elements in the lid. This combination of top firing and side firing provides more even heating for glass objects, which tend to be more horizontal than pottery. A glass kiln also provides slower cooling, which is necessary for the glass to anneal and become less brittle.

GLASS PAINTS —  Pigments, powdered or liquid glass paints applied to a glass surface

GLASS POWDER — Glass that has been ground into a fine powder.

GLASS SAW —  Used to cut any glass shape out of any type of glass, quickly and with minimum glass waste. Types include; ring saw, band saw, etc

GLASS SIFTER — Used to sort various sizes of frit or to dust glass with powder glass.

GLASS SEPARATOR — A protective coating used to keep glass from sticking to the kiln floor and shelves. Also known as kiln wash or shelf primer.

GLASSBLOWING — The technique of forming an object by inflating molten glass gathered on a blowpipe. The glass is then manipulated and shaped by rolling it on a marver, swinging it, and shaping it with tools.

GLAZE —  A functional or decorative coating applied to the surface of pottery that becomes glass during firing. Glazing can be done to waterproof pottery or to add color or texture. Different visual effects are achieved with gloss, matte, or opaque glazes, or by adding an overglaze or underglaze.

GLAZE FIRING —  When clay is fired in a pottery kiln after the application of a glaze. Glaze firing is usually the second firing and takes place after bisque firing.

GLORY HOLE —  A high-temperature, gas-fueled chamber used to reheat and maintain the temperature of glass pieces while being worked on. The glory hole contains an oxygenated gas flame that maintains a temperature of 2200° F.

GLUE CHIP —  A texture created on the surface of cold glass by applying hot animal glue and allowing it to dry under controlled temperature and humidity conditions. As the glue dries and contracts, it chips the glass surface in a natural and attractive pattern, likened to frost on a window pane.

GOLD PEN —  Pre-filled pens for adding fine trim, detailed designs, enhancing and personalizing your glass.

GOGGLES —  Used to protect your eyes while working with glass. Not used during firing techniques, will not protect against glare, ultraviolet and infrared radiation.

GRAAL —  A type of decorative glass developed by Orrefors of Sweden in 1916. The design is carved, engraved, or etched on a parison of colored glass, which is then reheated and cased in

GRAVERRE —  The graphite or charcoal drawing is fused between layers of the glass sheets. The technique is ideal for capturing the spontaneity of drawing.

GREENWARE —  greenware is the term for pottery that has been shaped on a pottery wheel but not yet fired in a pottery kiln. Greenware must be air dried before firing. Bone dry greenware is ready for firing but extremely fragile. The stages of the greenware drying process are wet, damp, soft leather hard, leather hard, stiff leather hard, dry, and bone dry.

GRINDER —  Electrical tool that is used for the precision shaping of glass.

GRINDING — The technique of removing the surface of an object with a rotating wheel fed with an abrasive, a thick layer of transparent glass of a different color, and inflated or by some other means. Using an abrasive wheel on a grinder to smoother or shape the edges of glass.

GROG — Clay that has been fired and then ground into granules of more or less fineness. Grog is considered a filler, and added to clay bodies for several reasons; it helps open a tight or dense body, promotes even drying, which reduces warping and cracking, and reduces overall shrinkage. Grog also adds tooth and texture to a clay body aiding in the ability of the body to maintain its form during construction.

GROZE —  The process of filing or chipping away small of glass.

GROZING PLIERS —  Used for chipping away small areas of glass. They have small serrated teeth.