The Science of Taming Fire: making glass

PROVIDENCE, R.I. (WLNE) — Gather Glass in Providence applies high heat to simple sand to make something very delicate: glass.

“Basically, it’s sand, soda lime, potash and then you can add anything from the periodic table of elements and it will change its properties,” Master Glassmaker Benjamin Giguere said. “It’s the only thing on the planet that can do that. There’s nothing else like it.”

For example, adding cobalt gives you blue glass, iron yields green glass. Boron oxide makes glass oven-proof and lead oxide makes fine crystal glass.

You can even add uranium to glass to make it glow.

“The old wives tale of you ever see an old window that’s thicker at the bottom, that’s bunk,” Giguere said. “It’s actually the process how glass is made. The glass does not slump over time. That’s not true.”

Glass is known as an amorphous solid, which is a frozen super cooled liquid. It has the physical attributes and crystalline structures of solids, yet it also had the molecular randomness of a liquid.

“The very last step is called the annealing process,” Giguere said. “Depending on the thickness of the piece, dictates how long the piece is annealed.”

The annealing oven is 900 degrees. Overnight the temperature is programmed to drop by 75 degrees every hour so that the finished products are ready for the next day.