How to Make Hand Blown Glass
Glass blowing is a technique used to form liquid glass into shapes, creating beads, jewelry and even ornaments. An instrument known as a blow pipe is used to add air, inflating the inside of the glass to create a bubble or blister. To start the process, a finely ground combination of sand, limestone and ash are poured into a fused silica crucible and placed in an electric furnace ranging at 1400 degrees. The heat from the furnace will melt the powdered mixture to form liquid glass.
Things You'll Need
- Electric furnace
- Sand
- Limestone
- Ash
- 250 ml fused silica crucible
- Gloves
- Safety goggles
- Annealing oven
- Blow pipe
- Pliers
Instructions
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1
Set and preheat the electric furnace to 1400 degrees.
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2
Fill the crucible 1/3 of the way up with the mixture of sand, limestone, and ash. Insert the crucible into the electric furnace. Fill the crucible with another 1/3 of the volume left in the crucible in 40 minute increments until the crucible is full.
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3
Remove the crucible from the electric furnace and stir the liquid glass to make sure the consistency of the glass is that of syrup or honey.
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4
Pour the liquid glass into a mold to cool and form a predetermined ornament shape. Place the ornament into an annealing oven for 14 hours. Let the mold cool completely before removing the glass ornament. A blow pipe may also be used to inflate and shape the glass while it is still hot.
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Touch the end of the blow tube to the surface of the liquid glass. Build up a decent amount of liquid glass at the end of the pipe. Continuously spin or twirl the blow pipe so the glass does not droop and become lopsided. Blow through the blow pipe, forming a bubble inside the glass. This will make a smooth sphere shape, forming your ornament. Spin the blowpipe with your hands to guide the glass and keep a round shape. Keep blowing through the tube and spinning the glass until you have achieved the desired size of your ornament.
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6
Use a pair of pliers to pull the top of the glass of the ornament and make a loop. This will allow a spot on the ornament to connect a hook so it may hang from a tree or shelf.
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Place the ornament into an annealing oven to gradually cool down. This is a slow process. If the ornament is cooled too quickly, it may form stress fractures. Remove the ornament from the annealing oven after 14 hours.
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Tips & Warnings
Always use caution when dealing with a furnace as well as liquid glass. Wear safety goggles and gloves at all times.
References
- Photo Credit deep-red glass pot and glass blue balls image by Maria Brzostowska from Fotolia.com
