March 13, 2009

The art of lampworking

Lampworking: The process of sculpting glass by twirling thin rods of colored glass over a gas-oxygen burner.

Let me introduce you to this fascinating technique I fell in love with the moment I tried it.

I melt glass like a meditation and it still is my passion.

Lampworking is also known as flameworking or torchworking. Early lampworking was done in the flame of an oil lamp, with the artist blowing air into the flame through a pipe. Although the art form has been practiced since ancient times, it became widely practiced in Murano, Italy, in the 14th century. Bohemian lampworkers also mastered the technique but like the Italians, kept the techniques secret. In the mid 19th century lampwork technique was extended to the production of paperweights, primarily in France, where it became a popular art form, still collected today. Only thirty or so years ago, some American artists started experimenting with the form.

After designing a piece, a lampworker must carefully plan how to construct it. Once ready to begin, the lampworker slowly introduces glass rod or tubing into the flame to prevent cracking from thermal shock. The glass is heated until molten, wound around a specially-coated steel mandrel, forming the base bead. It can then be embellished or decorated using a variety of techniques and materials. The different colors of glass must be carefully selected for compatibility with each other and all parts of the workpiece must be kept at similar temperatures lest they can shatter. Once finished the piece must be annealed in an oven (kiln) to prevent cracking or shattering.

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 uniform throughout. The time necessary for this depends 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't generate internal stresses, and then 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 may crack or shatter due to a seemingly minor temperature change or other shock.
The whole process takes approx. 12 hours and it is all so fascinating!
Hope you have a terrific day and a great week-end:)