Tool Tuesday: the furnace

The bulk of my making happens in the glass studio–often called a hot shop. And the heart of any hot shop is the furnace.

This rather giant furnace lives at DC GlassWorks and Sculpture Studios, a public access glass and metal facility in Hyattsville, Md.

Inside is a crucible filled with glass.

A peek inside the furnace during maintenance. Here you see the crucible before it has been enclosed inside the furnace. After being bricked in, the cover is removed and the crucible itself filled with glass that is then brought up to temperature.

The crucible and furnace at DC GlassWorks holds more than 500 pounds of clear glass. Once it is turned on, the furnace runs 24 hours a day, seven days a week, every day of the year. If the power goes out or something goes awry with the gas and air mixture that keeps things hot, someone needs to check the furnace. It doesn’t matter if it’s 2 am or snowing, the furnace needs to be on.

The glass inside the crucible “rests” (when not in active use) at 1980 degrees fahrenheit. To work (blow glass), the temperature of the glass is brought up to 2080 degrees fahrenheit. As the crucible is restocked with additional glass weekly, the temperature reaches 2300 degrees fahrenheit.

When you step up to the furnace to gather clear glass, it’s a bit like stepping in front of, and then looking into, the sun.

Taking a gather of clear glass from the furnace. Moving quickly is good–it’s hot!

The size of your gather of clear, what you add or take away from it and how you shape it from there are all open to your own design.

The furnace and the clear glass within are the building block.