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Anneal
The process of heating a lampwork piece in a kiln (or annealing oven) in order to: 1) stabilize (or even out) the temperature throughout the piece and 2) to slowly cool the object (down to room temperature) in phases in order to prevent stress and cracking.

There are four phases in the annealing process: the soak period, the initial cooling period, the second cooling period and the final cooling period. The kiln’s temperature remains the same during the soak period. The gradual reduction in temperature varies during the next three phases according to the type of glass, as well as the thickness of the object being annealed. The period of time between the soak period and the initial cooling period is the most important. The initial cooling period reduces the temperature down to the glass’ strain point. Each type of glass has a different stress point, so the initial cooling period will be different as well. These cooling periods are refered to as “ramping down”.

Check with your glass distributor for suggested annealing schedules.

Kilns with digital controllers can be programmed with annealing schedules which saves from having to to manually adjust a temperature controller during the annealing process.

Annealing Oven/Kiln
Used to anneal lampwork pieces. (See Anneal)

Bead Release/Separator
A liquid, clay-based product used to prevent molten glass from fusing with the steel mandrel used to make lampwork beads. Mandrels are dipped into bead release and are dried (either air or flame) before using. Some bead release products are specially formulated for flame drying.

Caliper
A tool used to measure the inside or outside diameter of an object. Brass calipers can be used with hot glass.

Cane
A pulled or twisted glass rod.

Case/Encase
The process of enclosing a glass object with hot glass. Typically, an opaque core is encase with clear or another transparent color. Encasing makes a core design or detail larger or more pronounced to the eye.

COE
Coefficient of Expansion or Coefficient of Thermal Expansion – The rate at which glass expands when heated. Glasses with differing COEs are not compatible because of the changes taking place on the molecular level and will crack or break apart when cooled.

Not all glasses with the same COE are compatible. Beginning lampworkers often discover different types/colors of glass and consider using the different glass without being familiar with the compatibility issues. Check with your glass vendor concerning the compatibility of the glass you are considering.

Compatibility
The ability of different glasses to remain fused without cracking or breaking once they have been annealed and cooled. Typically glasses with the same COE are considered compatible, but there are exceptions. Also, small amounts of an incompatible glass can be applied to a base glass. Ex..small amount of frit on a bead.

Devitrification
The process in which the surface of glass changes from a vitreous to a crystalline condition. The smooth surface of the glass will loose its color and will look white and powdery.

Dichroic or Dichro Glass
Glass which as been specially formulated and exhibits a variety of reflective colors.

Didymium Glasses
Glasses worn by lampworkers to protect themselves from Ultraviolet (UV), visible and Infrared (IR) radiation.

Didymium glasses are used with Soda-Lime glass (also called soft glass). Eye protection/glasses used with Borosilicate glass (also called hard glass) have different properties than glasses used with soft glass.

Drawn
The process of pulling hot glass. Rods and stringers are drawn or pulled from larger gathers of glass.

EDP (See Devitrification)
Evil Defitrifying Purple

Encase/Case
The process of enclosing a glass object with hot glass. Typically, an opaque core is encase with clear or another transparent color. Encasing makes a core design or detail larger or more pronounced to the eye.

Etch
The process of either creating a matte finish to a glass object by submerging it into an acid solution or the process of cutting into the glass using glass cutting tools to create a design.

Filigrana
A glass rod with a colored core and a clear encasing.

Flame Cone
The inner yellow/white cone area of the flame.

Flame Polish
The process of using the flame to lightly and evenly reheat glass in order to remove tool marks left by marvering pads, presses, etc.

Flamework
Another term for lampwork.

Flashback/Arrestor
Devices connected to fuel and oxygen sources which prevent reverse flow and to quench a flashback flame.

Frit
Glass which as been crushed or broken up into various sizes and is used as a decorative treatment. Frit can be purchased in the following sizes: powder, fine, medium and coarse.

Fusing
Heating pieces of glass together until they bond.

Gather
A gather is a molten glob of glass on the end of a glass rod, tube or stringer. To gather is to allow molten glass to collect on the end of a glass rod, tube or stringer.

Glass
The main ingredients in glass are silica, calcium oxide (lime) and sodium carbonate. The two types of glass commonly used in lampwork are soda-lime glass (soft glass) and borosilicate glass (hard glass). Lampworkers use solid glass rods designed for lampworking, as well as glass shards, frits and powders.

Although the glass most of us see and handle every day appears to be a solid material, glass shares characteristics of the atomic structures in supercooled liquids.

Hard Glass
Borosilicate glass (Boro) is a mixture of boron, silicate sand, soda and ground lime. Boro glass has a higher melting point and requires a torch which can heat the flame sufficiently. Boro glass is very popular because of its beautiful and brilliant properties, but several glass manufacturers have developed new soft glasses with similar characteristics.

ID
Inside Diameter

Kiln/Annealing Oven
Used to anneal lampwork pieces. (see Anneal)

Lampwork
Lampwork is a term for a hot glasswork method – the method of using a flame to melt and form glass into handmade glass objects such as beads, marbles, and sculptures. An example of cold glasswork is stained glass art or any glasswork process that does not involve heating the glass in order to shape it. Fusing and slumping are considered to be warm glasswork.

Mandrel
A steel rod used to make lampwork beads. Mandrels are available in different diameters as well as lengths. Popular sizes of mandrels are 1/16”and 3/32” diameter. Also popular are the 5/32” and 3/16” sizes used to make Pandora style beads. The 3/16” are typically used if the beads will be silver lined. Mandrels are dipped into bead release and dried before using.

Marver
The process of using a flat or semi-flat surface to shape hot glass. Lampworkers often use marvering paddles made from brass or graphite.

OD
Outside Diameter

Propane
One of the fuels which can be used for lampworking.

Rake
A tool with a bent or straight pointed end used for manipulating the surface of hot glass.

Regulator
An attachment which controls the flow of gas. An oxygen regulator is used with a compressed oxygen tank and a separate fuel regulator is used with a fuel tank. Oxygen concentrators do not use external oxygen regulators.

Rod Rest
A tool used to support hot glass and tools in order to prevent them from touching a work surface.

Shorty
A term used to described a glass rod which has been used or broken into a short rod.

Shorty/Rod Holder
A tool used to hold a short rod of glass to prevent fingers from getting too close to the flame.

Soft Glass
Soda-lime glass – A popular glass used to make lampwork beads.

Softening Point
The temperature at which glass will begin to sag or move.

Strike
The process of cooling and reheating glass through one or more cycles in order to ‘develop’ its color. Some glass will loose/change its color when heated. This type of glass is referred to as striking glass. If the color of the glass completely disappears, striking is necessary to regain color. Different striking glasses require different reheating and cooling times and places in the flame. Check with your vendor concerning the glass you are considering.

Stringer
A thin (.02-3.0mm), typically straight and long piece of glass used to add additional glass to areas in order to fill in places or even up edges, etc or to decorate.

Thermal Shock
The effect of glass being cooled or heated too quickly, causing cracks or fractures.

Torch
An apparatus used to melt glass. Lampwork torches use a fuel source and an oxygen source to create and maintain a flame with sufficient temperatures to melt glass. Different types of torches are used with different types of glass and/or different size pieces. A Minor Bench Burner is just one of the popular torches beginner lampworkers use.

Torchwork
Another term for lampwork.

Tungsten
A metal used for making lampwork tools which can be used in the flame and will not readily fuse to glass. Lampwork tools made with brass and graphite are also available.