Furnaces Withstand Temperatures Of 3000¡F


The glassblower's furnace begins with an inner tank made from 
thick refractory bricks that can withstand contact with 
molten glass and temperatures up to 3000¡F. Four of these 
bricks, each 18 x 12 x 3 inches, are formed into a tank, with 
another brick serving as the bottom of the tank.

A second layer of bricks that can withstand temperatures up 
to 2300¡F is stacked around the outside of the tank. The top 
of the furnace is a cement crown covered with four inches of 
insulating wool. At the very top is a burner that fires the 
glass furnace.

Each hour, the furnace uses the same amount of energy used by 
an average-sized house on a cold winter day.

A furnace, which costs from $3,000 to $4,000, lasts about 
five years before the glass becomes too corrosive and it 
wears out.


Steve Martin (left) and John Rundle continue a centuries-old 
glassblowing tradition begun by Ancient Romans.

Photo by Michael Haynes.


(Clockwise from top) John Rundle gathers molten glass onto 
his blowpipe, shapes the glass and blows a large bubble. 
Photos by Michael Haynes.

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