Closeup of Billet Casting by Melanie Rowe
System 96 casting billets are hand poured into handy squares to minimize bubble count, and are made from our unique ultra-low-devitrification glass. They are ¾” x 7” x 7” (1.9cm x 16.8cm x 16.8cm) and weigh approximately 3.4 lbs (1.5 kgs) each. System 96 billets are annealed, and are easy to cut in straight lines with a simple score and a thick glass breaking tool or a sharp tap on the opposite surface. Like cutting sheet glass, this takes a little practice and confidence, but once you get the knack of it you’ll never look back.
Billets can be laid into molds flat, stacked, or shingled. Shingling may provide the lowest bubble count results. To achieve a clean top edge on open face castings, be sure to hold glass back from the mold edges a ½” or so, so that the melting glass touches the bottom edge first, then rises up the mold wall. You want to avoid letting the melting glass touch the top rim of the mold until very late in the firing.
While we make a big effort to maintain consistent color from run to run over many years, the extremely light colors in casting products are prone to some variation. This is most evident in large castings with simple coloration, or in very thick castings (2" plus), and more so for installations in front of a simple white background.
If there are multiple colors in a single piece, or if the piece is to be displayed in a busy or colorful environment, it is highly unlikely that slight color variations in the light casting colors will be noticeable even to the trained eye. So, if you are planning a large single color or very thick cast project, please request that your casting glass come from a single production day or lot.
Questions about firing schedules? When planning a firing schedule for heavier castings, please refer to our Firing Guidelines. You will find that System 96 casting products can be fired at slightly lower temperatures than 90 COE ‘Bullseye Compatible’ or Artista fusible glass products, so you save on firing costs.
If you are working in smaller scale or in closed molds, and find you are usually cutting billets down to fit into your mold, consider using Billet Chunks. These are pieces pre-cut from whole billets, so you benefit from the low bubble count of the billet form, but are likely not to have to cut them to size.