Stained Glass Art
Although the origin of stained glass is not known, this form of art continues to decorate churches, homes, businesses, and restaurants. Stained glass art uses pieces of glass used in a mosaic-like form to create patterns, objects, or scenes in windows, wall hangings, lamps, and more.
A piece of stained glass artwork begins as a pattern on paper. The pieces of the pattern are then constructed by scoring and breaking sheet glass. Once the pattern is cut out of various colors and textures of glass, the glass piece edges are ground to create a rough surface. Copper foil with adhesive backing is then wrapped around each piece of glass, and the pieces are then fluxed and soldered together using a soldering iron and solder. Finishing touches include adding patinas, wires for hanging, lamp bases, or picture frame backings.
Glass is most commonly made from silica or sand (SiO2), but can also include anhydrous boric acid and anhydrous phosphoric acid. Because the melting temperatures of glasses are relatively high (~1800oC), fluxes are added to allow the glass to melt at lower temperatures resulting in more cost effective processes. Fluxes include soda ash, potash, and lithium carbonate. Impurities are added to give glass color such as these impurity:color pairs, gold(Au):red, Cobalt (Co): blue, Silver (Ag): yellow, and Copper (Cu): green and red. More information on processing glass and glassblowing can be found on the Corning Museum website at www.cmog.org. Both the type and texture of glass depends on the impurities and processing during manufacturing. Glass types include cathedral, opalescent, translucent, streaky, and wispy. Glass textures include artique, baroque, glue chip, hammered, iridescent, seedy, and waterglass. Descriptions of the types and textures can be found at the AmeriGlas Stained Glass web site.
Stained glass solders used are most commonly 60/40 tin/lead. The health issue involving lead is leading the semiconductor industry to develop new solder materials that are "lead-free", and these "lead-free" solders can also be applied in stained glass art. The melting temperature of lead is 327oC and of tin is 232oC, however a 60/40 solder has a lower melting temperature of ~160-170oC. Solder temperatures must be regulated to assure a proper bond between the two pieces of glass.
Many aspects of the processing and composition of materials used in the art of stained glass need to be taken into consideration in order to create a beautiful piece of artwork from a pattern.