sufficient to completely melt the frit without melting of the assemblage preferably to between 650 and 750 degrees c depending on the composition of glass used alternatively the assemblage is rapidly heated to about 550 degrees c at a suitable rapid rate of heating preferably at about 600 degrees c per hour then removed from the oven or furnace to melt the frit with a flame torch once the frit is melted the assemblage is returned to the furnace when the frit is melted the glass composite of the present invention is created the resulting glass composite is rapidly cooled to a temperature intermediate between a frit melting temperature and a room temperature preferably just above the annealing point of the assemblage usually 300 550 u00b0 c at a rapid rate of cooling and annealed held at the intermediate temperature for a period of time preferably up to 2 hours most preferably for about 10 20 minutes the composite is then slowly cooled to room temperature preferably at a rate of about 50 degrees per hour the following examples illustrate the present invention and are not intended to limit it in any way this example illustrates the preparation of a lead free glass composition of the present invention the raw materials according to table 3 were combined in a quartz crucible table 3______________________________________raw materials grams______________________________________silica supersil 400 sio sub 2 41 8boric anhydride fisher 18 1soda ash na sub 2 co sub 3 1 5potash k sub 2 co sub 3 21 7lithium carbonate.