Using centuries old techniques, one of the KOG glass blowers fashions a blown rondel by hand
Every year at Kokomo Opalescent Glass our glass blowers make thousands of rondels, big, small, and in between. Today Daniel is making small blown glass rondels.
Because of their small size, these rondels only require a single gather of glass each. This order calls for several hundred 18D dark amber rondels at 2 5/8” across.
A blow pipe and a punty will be used. The blow pipe is a hollow metal tube with one end built up to hold the molten glass and the other has a mouthpiece; the punty is a metal rod.
As with most things in our hot glass studio, a blown rondel starts with a gather of glass. Daniel begins by inserting the blow rod into a pot of molten 18D dark amber glass. Larger rondels will start with a larger gather, while smaller ones, logically enough, begin with less.
The gather is taken to the marver table where it is rolled to begin the shaping process. A gentle puff of air is blown into the pipe, once the breath reaches the molten glass it expands due to the heat. This expansion creates a glass bubble on the end of the blow pipe. More breath creates a larger bubble.
Daniel now takes the bubble to the furnace to warm it back up, if the glass cools too much it becomes difficult to work with. On the way to the furnace he will swing the blow pipe, allowing gravity to help stretch and shape the glass
Properly warmed, the glass bubble is now ready for more shaping. A tool called the jacks is used for this as well as a wooden paddle. The glass may require more expansion by means of air being blown down the pipe.
The bubble gets hung up while Daniel prepares the punty for transfer. If the bubble was left on the work bench, gravity would begin to deform it; by hanging it this way, gravity can continue to shape the glass.
The punty gets a small gather of clear glass that is shaped on the marver table. The jacks are used to control the transfer from the blow pipe to the punty. Since the blow pipe is no longer needed for this rondel, it is set aside while the glass gets warmed again.
There is now a small hole at the point where the bubble had been attached to the blow pipe. If you look closely you can see this hole as it is warmed in the glory hole.
The jacks are used to open the hole wider, stretching the glass into new and interesting shapes as it is transformed into a rondel. The glass has to be kept warm during the entire shaping process so it may require additional trips to the furnace. The rondel will be measured during its development to make sure it is going to be the correct size.
In a production environment, the glass blower may spray air onto the tip of the punty. As you might have surmised, this makes the glass more fragile where it connects to the rod which in turn makes it easier to release the glass from the punty
The rondel is now taken to the annealing oven, where a gentle tap on the punty will release it. If the glass was to cool at room temperature, it would crack and become useless. The annealing oven slowly cools the glass; in about a day this rondel will be ready for final inspection before getting shipped to the customer.
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