2.2 Raw materials for making glass

 

 

 

 

 

 

 

 

 

 

 

 

are made according to exact formulas specific to the factory.To begin to produce glass, all the components are mixed together and melted in large fireproof clay pots inside a furnace [2.3]. These clay pots must be replaced periodically [2.1] because the in­tense temperatures cause them to crack and cor­rode. Tiny pieces of clay can break off into the molten glass leaving imperfections or “stones” in the crystal. Paperweight maker Charles Kaziun described the fragile nature of these pots in an article published in the 1962 PCA Bulletin :

Glass pots are noted for their sensitivity to sudden changes of temperature and are subject to cracking while in use and leaking out the molten glass. Even before a pot is put into service it has been known to break just bringing it up to heat. Once the pot leaves the maker’s factory, all risks lie with the buyer except for obvious breakage that may occur in transit. However, some cracks only show up the first time it is heated and filled with batch only to have the glass run out. . . That is a sad day for that factory.

After the raw materials have been heated to temperatures exceeding 2600° Fahrenheit, the molten mixture is “boiled,” or stirred, to eliminate any imperfections in the melt and make the glass

 

2.5 Modern furnace at Parabelle Glass

2.7 Latticinio arranged on metal template

2.6 Melting premade glass slug with torch

 

2.8 Molten glass on pontil rod

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

more homogeneous. At this point, the glass is a red-hot liquid. As it cools to a working tempera­ture, it can be manipulated and shaped with an array of special tools [2.4].

Paperweights may be constructed in two gen­eral ways depending on the kind of equipment used. Some glassworkers or factories have fur­naces to produce molten glass [2.5]; others use torches or lamps to melt a slug of premade glass [2.6]. Yet, many aspects of the process are the same. Once the decorative elements, such as millefiori canes or lampwork figures, have been created, they are arranged on a metal template and heated to just below the melting point [2.7]. This is done to avoid cracking when hot glass is added. A metal collar is placed around the arrangement. The glassworker gathers a small ball of molten glass on the end of a long iron rod [2.8], rolling it and working it into shape on a metal plate or marver. The red-hot glass is then lowered into the collar to pick up the pre­heated design [2.9].

If the worker has a furnace, the canes or design elements are placed in the template face down [2.12]. They are picked up in this reverse position by the first gather of glass, which forms the ground of the paperweight [2.10]. If the glassworker uses a lamp or torch to make the decorative elements, they are placed in the collar in an upright position. Then the first gather flows in on top of the design, sometimes aided by a vacuum. The glass is blocked and shaped [2.13].