Glass has been used for hundreds of years in millions of different items and it is an amazing material that is often taken for granted. We use it in our cars, buildings, light bulbs and wine glasses, but few people know exactly how glass transforms from raw materials into the functional molded end products. Lets take a look at the required procedures for making glass.
1.) The raw materials of glass are sand and some additional elements. The most common form of sand used is called Silica, and this is combined with specific amounts of soda ash and limestone. The quantities of the ingredients effects the qualities of the glass, and other materials can be added to change the colour of the glass or alter its strength etc. For example, a glass blower might add a small amount of red dye to the mix to make pink champagne glasses.
2.) The mixture is heated to a temperature of around 1700oC. At this temperature the minerals in the mixture all become liquid and blend together. Very large furnaces are needed to generate the heat to melt glass. Electric powered furnaces are on the increase, although traditional glass blowers still prefer to use classic coal fires. When the glass mix is in a molten state, it can easily be manipulated and sculpted or blown in to specific shapes. This is a skill that takes years to master and is very easy to get wrong.
3.) After the glassblower has shaped the piece, it is then allowed to cool down. This cooling process is very important as it can have a huge influence on the glass qualities, including strength, clarity and how it shatters. For example, whisky glasses are often cooled slowly as this makes them less susceptible to scratches, although the refractive index is slightly lower than other types of glass
Tags: crafts, glass, glass blowing, making