The Glass Kiln
The main elements in the production of crystal glass are sand and potash. Precious crystal and lead crystal are melted in our glassworks at a temperature of about 1400°C in the so-called ‘pot kilns‘. These have a capacity of 600-900 kg of glass and are never extinguished; the furnaces have been in operation without interruption for several years.
The most important man in the glass production is the ‘gaffer’ . He blows slowly and accurately with the blowpipe in the air, and a small glowing bubble results – the ‘gather‘. An appropriate amount of glass is removed and then gently blown by glassmakers into a wooden or metal mold. The glass is blown gently with constant, steady turning until it has adapted to the form – this is the ‘parison‘.
Blowpipe in the furnace
Glass blown into a wooden mold
As a special variant, so-called “optical- bubbles” demonstrate a very old technique unique to the traditional craftsmanship of OERTEL. The preparation of these ‘optically blown‘ pieces places a high demand on the glassmakers‘ skill, and years of experience are required. The glass is already decorated and still hot. The cased glass with hot ‘gather‘ is lowered into a ribbed or patterned cylindrical shape, and then inflated just so far as to allow the pattern of the preform to be imprinted in the product. The more malleable crystal glass is then blown carefully into its final shape in the flask; this the pre-embossed pattern is obtained. A rapid rotation allows the ribbing to be twisted in spirals, creating fascinating crystal works of art.