Glossary

Annealer

An insulated box, similar to an electric kiln, designed to cool glass slowly at a specified rate. If hot glass is cooled too quickly, the stress on the glass will cause it to be unstable and through time cause it to break.

Batch

A mixture of the basic components of glass (silica, soda, or potash and lime). When heated to its melting point, approximately 2400°F, the mixture becomes glass.

Bits

Small amounts of molten glass on the end of a punty that are brought by an assistant and applied to another hot glass form.

Block

A wooden tool that is kept wet and used to shape glass.

Blowing

The process of creating objects from hot glass. The hot glass is gathered on a blowpipe. As the object is formed the blower and/or assistants blow through the pipe creating a bubble that can take many shapes.

Blowpipe

An iron or stainless steel tube shaped for blowing glass.

Box

Another term for Annealer.

Bubble (Seeds)

Small pockets of air that form when gas is trapped in hot glass. Bubbles can be formed either intentionally during the working of the object or accidentally during the gathering or melting process.

Cap

Air is blown into the pipe and quickly closed off at the end of the blowpipe with the blower's thumb so that the hot air expands within the hot glass and/or keeps the glass from collapsing.

Casting

The process of pouring hot glass into molds of various materials, the simplest being sand. Casting can also be done from the kiln, where the glass starts in a cold state then melted into plaster/silica molds.

Charge

Shoveling batch into a furnace to melt the glass into its workable form.

Check

A crack in glass caused by improper annealing and/or compatibility of the glass and color.

Cold Shop

A workshop with equipment to grind, polish, engrave and/or cut glass and/or to add surface details to finished glass pieces.

Cullet

Cooled, glass pieces that have been previously melted and that will be recycled.

Dip

Gathering hot glass from the furnace with a blowpipe or punty.

Etching

Creating a surface design by cutting the surface of finished glass with a tool or by applying of acid.

Flameworking

The process of using a torch to heat up rods or tubes of glass that will be manipulated into different shapes. Also called lampworking.

Furnace

Equipment used for melting batch and keeping glass at a constant temperature. The temperature of the furnance ranges from 2150°F working temperature to 2400°F charging temperature.

Fusing

Heating pieces of glass until they bond. This process is achieved within an annealer.

Gaffer

The leader of the glassblowing team.

Gather

Also called a dip. The process of collecting molten glass from the furnace on a pipe, punty or gathering iron.

Gathering iron

A long rod with a large ball at the gathering end used to gather hot glass from the furnace, usually for the hot casting process.

Glory Hole

A heavily insulated cylinder, kept between 2100°F and 2300°F, which is used to reheat hot glass as it is being formed and manipulated in the Hot Shop.

Heat Shields

Protective devices that protect the glassblowing team from excessive heat coming from the glass as it is being worked and from other hot shop equipment, such as the glory holes.

Hot Shop

A workshop where molten glass is blown, cast or manipulated.

Jacks

Bladed tools used by glassblowers to shape molten glass. They come in various shapes and sizes to accomodate the work being made.

Laminate

Joining two pieces of glass by using heat or an adhesive.

Lampworking

Another term for flameworking.

Lip

The rim of a vessel.

Lip wrap

A thread of glass which is applied to the mouth of a vessel with a punty.

Marver

A large, flat surface on which hot glass is rolled when it is attached to a blowpipe or punty.

Melt

A term used loosely to describe the process of heating materials to make glass or to recycle glass.

Mold

A form used for creating specific shapes with molten glass. Hot glass can be poured or blown into a mold.

Optic Mold

An open mold with a textured interior into which a parison of hot glass is blown to create patterns in glass.

Paddle

A wooden board with a handle that can be used to shield the gaffer from excessive heat or to smooth or flatten hot glass.

Parison

A partially inflated gather of hot glass on the end of a blowpipe.

Pipe

Another name for blowpipe. A stainless steel or iron tube on which hot glass is gathered and through which the glass is blown.

Pipe Cooler

A device used to cool the shaft of the blowpipe after a gather. The pipe is placed across an open barrel of cool water; the water is pumped over the shaft of the pipe until it is cool enough to handle.

Pole turner

A member of the glassblowing team who turns the blowpipe as hot glass is being blown or manipulated.

Pontil or Punty

A metal rod that is used to gather a small amount of hot glass, which is then transferred to the object or used to transfer the object making it possible to work the other end.

Pot

The container in the furnace in which batch is melted. Also known as a crucible.

Prunt

A small bit of hot glass applied as decoration.

Pyrometer

Special thermometer used to measure high temperatures in hot shop furnaces, annealers/kilns and other equipment.

Respirator

A face mask used to filter out harmful airborne particles.

Sandcast

Pouring hot glass into a mold made of casting sand.

Seeds

Very small air bubbles found in molten glass.

Shard

A small piece of colored glass that can be melted into a hot glass piece for decoration.

Shield

A paddle used to protect a gaffer or other member of the team from excessive heat.

Slump

Heating glass so that it softens and changes shape without becoming molten.

Stippling

Tapping the surface of a hot glass object several times with a tool to produce a decorative finish.

Thermal Shock

This occurs when glass experiences an extreme change in temperature, either a drastic increase or decrease. This will cause an inconsistency in the structure of the glass, creating instability and eventually cracking the glass.

Thread

Strand of hot glass that can be applied to a rotating parison to create a pattern or surface decoration.

Transfer

Attaching one piece of hot glass to another, usually using a punty and breaking it free from its original pipe or punty, enabling the glass artist to work the other end.

Tweezers

Tong-like tool used to grab or manipulate hot glass.

Wax

Beeswax, which is most commonly used, is applied to the blades of the jacks to prevent scratching or marking the surface of the hot glass.

Wrap

A strand of hot glass applied to a vessel.

Yoke

A metal stand on which blowers rest their pipes or punties while re-heating glass in the glory hole allowing for easy rotation.