What is Lampworking?

Lampworking is the artform of using a torch to melt and shape glass into beads - sculptures etc. Although the art form has been practiced since ancient times, it flowered in Murano, Italy in the 1300s, and spread from there to the rest of Europe.

Early lampworking was done in the flame of an oil lamp, with the artist blowing air into the flame through a pipe. 

Most artists today use torches that burn either propane or natural gas for the fuel gas, with either air or pure oxygen as the oxidizer. 

There is an enormous quality difference between artist-made lampwork beads and those made in bulk. If you want exceptional beads for your jewelry designs or arts and crafts projects, look for beads made by a self-representing artist. 

 

Glass selection

Lampworking can be done with many types of glass, but the most common are soda-lime glass, sometimes called "soft glass", and borosilicate glass, also called "hard glass". 

Different types and colours of glass must be carefully selected for compatibility with each other, both chemically and in terms of coefficient of thermal expansion (COE).

Chemically, some colors can react with each other when melted together. This may cause desirable effects in coloration, metalic sheen, or result in an aesthetically pleasing "web effect". It also can cause undesirable effects such as unattractive discoloration, bubbling, or devitrification.

Glass with incompatible COE, mixed together, can create powerful stresses within a finished piece as it cools, cracking or even violently shattering the piece. Different major types of glass, e.g., borosilicate and Moretti, are not compatible with each other. 

Tools

Tools for lampworking are similar to those used in glassblowing. Graphite or steel pads, rods, and other shapes are used for marvering the glass. Brass, graphite, or wooden molds (usually of apple or cherry wood) can be used to mold the hot glass. Tungsten picks can be used to drag glass around on the surface, or to bore a hole through a piece.

Methods

Annealing, in glass terms, is heating a piece until its temperature reaches a stress-relief point, that is, a temperature at which the glass is still too hard to deform, but is soft enough for internal stresses to ease. The piece is then allowed to heat-soak until its temperature is even throughout; the time necessary for this varies depending on the type of glass and thickness of the thickest section. The piece is then slowly cooled at a predetermined rate until its temperature is below a critical point, at which it can no longer generate internal stresses, and then the temperature can safely be dropped to room temperature. This relieves the internal stresses, resulting in a piece which should last for many years. Glass which has not been annealed will usually at least crack, and can shatter due to a seemingly minor temperature change or other shock.