Our 800 pound furnace tank was running low on glass. So it was time to make some more. This is very long process, we started at 2am!
Ever wonder what glass is made of? how it’s made?
What is glass made of?
Glass is sand with other ingredients added to make it melt easier. The fewer ingredients added, the higher the temperature it melts at and the less it expands and contracts. Almost pure sand would result in quartz, next down is borosilicate glass (Pyrex), lower down from there are soda/lime glasses, lower than that are Sodium Silicate which is a liquid at room temperature. Handling glass batch requires safety practices including cleanup, keeping chemicals safely, and using a respirator.
What type of glass do you use in your studio?
In our studio we use Spruce Pine Batch, which is a soda lime glass. It is made from soda ash, limestone, feldspar, lithium carbonate, sodium nitrate, zinc oxide, barium carbonate, fluorspar, antimony oxide. Batch is the raw materials that are melted into glass. The process of melting batch is called charging and is quite time-consuming. Our furnace requires about 24 hours to charge and cook the batch until it is relatively bubble-free.