Glossary of Lampworking Terms

• annealing -- A process of heating glass to release the strain introduced in the formation of the piece.
• blow hose -- A hose made of neoprene with a swivel on the working end designed to allow the artist to blow air into a piece while maintaining both hands on the piece.
• COE -- Coefficient of Expansion. The relative amount that a material will expand when heated.
• cold seal -- A cold seal is applying a temporary punty weld that can be broken off. With boro glass you want your punty glowing orange and the piece you're puntying to a little cooler. With soft glass you need to wait 30 seconds or more from a white hot punty, with boro it is like 10-15 seconds. Press together with a medium/light touch. The rods should feel soft but firm when pressed together. When you have a cold seal, you cannot heat the seal up too hot or it will not release. When you want to take your cold seal glass punty off, simply flash seal (make sure it's fairly cold) for 1-2 seconds in flame and then tap punty close to the seal on top of your torch or maver or table. Practice makes it, this trick is well worthwhile.
• compatibility -- Glasses that have the same COE are said to be compatible
• dichroic glass -- Glass that has been coated with a thin layer of metallic oxide. Dichroic coatings transmit certain wavelengths of light while reflecting others, creating an interference effect similar to iridescence.
• flaring -- The process of expanding the opening of a bubble or tube through centrifugal force spinning or expanding jacks. A goblet's foot base is flared open.
• frit -- ground up bits of glass from sand size to rock salt size
• fuming -- a process of applying layers of gold or silver to glass rods or tubes. The metals are vaporized using a torch which then stick to a glass rod or tube in it's path in the flame.
• gather -- a mass of molten glass on the end of a rod or tube
• melting point -- The temperature which below glass acts like a solid and which above which it can be shaped.
• paddle -- usually made of graphite, a flat shaped tool on a handle used for shaping glass
• punty -- A punty is a rod that is attached to the glass used to spin and rotate the glass. A punty can be made from either glass or from steal. A punty can be either solid just for holding on to the glass or hollow used for blowing the glass.
• sodium flare -- A bright flame resulting from the reaction of an oxygen-rich flame and the surface of glass containing sodium. It is protection from this that is the main purpose of didymium glasses.
• thermal shock -- the strain on a piece of glass caused by sudden temperature increase or decrease resulting in a mild or violent cracking