How to Bend Glass
Follow safety precautions., Find a heat-proof structure with the desired angle., Turn a Bunsen burner on medium or high., Lower the glass slowly into the flame at the desired bend point., Rotate the glass as you heat., Bend the hot glass around the...
Step-by-Step Guide
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Step 1: Follow safety precautions.
Wear safety glasses whenever handling hot glass.
You should only try this with long pieces of glass, which you can safely hold without putting your hands anywhere near the flame.
Hold hot glass using both hands, with each hand on an opposite end of the rod.
For short pieces of glass, clamp the glass to a ring stand or light vise, and use a torch instead of a Bunsen burner.
Follow these instructions, but instead of rotating the glass, rotate the torch completely around the point you want to bend, as you heat it.Keep a container of water or a fire extinguisher nearby, just in case. -
Step 2: Find a heat-proof structure with the desired angle.
For a 90º (right angle) bend, you can use the base of a ring stand, available from laboratory supply stores.
For other angles, you may need to create this yourself by clamping and bending a piece of sturdy sheet metal.
If you don't mind imprecise angles, you may skip this step and bend the glass by hand once it is hot, grasping only the two cool ends. , Attach the burner to a gas source, open the valve on the source and the base of the burner, then light the flame using a lighter or torch.
Adjust the air flow valve on the side of the burner until the burner produces a tall, blue flame.
Ideally, use a "wing top" burner attachment to create a wider flame, for a smoother bend.These are sometimes called "fishtail burners." If you are using glass "stringers," or small glass rods less than 2mm (0.08 inches) thick, you can use a candle flame instead. , Always begin applying heat slowly, or the glass will have a high risk of cracking. , Hold the glass so the point where the bend will occur is directly in the tip of the blue flame.
Rotate the glass slowly and constantly, and move it from side to side to heat approximately 5 cm (2 in.) of its length.Heat until you feel or see the glass begin to sag at that point. , If heated sufficiently, the glass should easily bend at that point.
Bend it around the heat-proof structure with the angle you require.
Make sure to hold the glass flat and steady during this bend. , Tighten the air intake valve on the side of the Bunsen burner, until the outtake cools to a single, thin flame with no hot, inner cone visible. , Holding the glass over this cooler flame relieves internal pressures that cause cracking, in a process called annealing.Rotate the bend in the flame while counting out 150 seconds, or time yourself with a stopwatch. , Place the glass on a heat-proof surface.
If you are in a shared workspace, write the words "Careful:
HOT" on a piece of paper next to it.
Leave it to cool to room temperature before using.
This can take several minutes. -
Step 3: Turn a Bunsen burner on medium or high.
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Step 4: Lower the glass slowly into the flame at the desired bend point.
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Step 5: Rotate the glass as you heat.
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Step 6: Bend the hot glass around the heat-proof object.
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Step 7: Reduce airflow to the burner.
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Step 8: Hold the bend over the flame for two or three minutes.
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Step 9: Let the glass cool.
Detailed Guide
Wear safety glasses whenever handling hot glass.
You should only try this with long pieces of glass, which you can safely hold without putting your hands anywhere near the flame.
Hold hot glass using both hands, with each hand on an opposite end of the rod.
For short pieces of glass, clamp the glass to a ring stand or light vise, and use a torch instead of a Bunsen burner.
Follow these instructions, but instead of rotating the glass, rotate the torch completely around the point you want to bend, as you heat it.Keep a container of water or a fire extinguisher nearby, just in case.
For a 90º (right angle) bend, you can use the base of a ring stand, available from laboratory supply stores.
For other angles, you may need to create this yourself by clamping and bending a piece of sturdy sheet metal.
If you don't mind imprecise angles, you may skip this step and bend the glass by hand once it is hot, grasping only the two cool ends. , Attach the burner to a gas source, open the valve on the source and the base of the burner, then light the flame using a lighter or torch.
Adjust the air flow valve on the side of the burner until the burner produces a tall, blue flame.
Ideally, use a "wing top" burner attachment to create a wider flame, for a smoother bend.These are sometimes called "fishtail burners." If you are using glass "stringers," or small glass rods less than 2mm (0.08 inches) thick, you can use a candle flame instead. , Always begin applying heat slowly, or the glass will have a high risk of cracking. , Hold the glass so the point where the bend will occur is directly in the tip of the blue flame.
Rotate the glass slowly and constantly, and move it from side to side to heat approximately 5 cm (2 in.) of its length.Heat until you feel or see the glass begin to sag at that point. , If heated sufficiently, the glass should easily bend at that point.
Bend it around the heat-proof structure with the angle you require.
Make sure to hold the glass flat and steady during this bend. , Tighten the air intake valve on the side of the Bunsen burner, until the outtake cools to a single, thin flame with no hot, inner cone visible. , Holding the glass over this cooler flame relieves internal pressures that cause cracking, in a process called annealing.Rotate the bend in the flame while counting out 150 seconds, or time yourself with a stopwatch. , Place the glass on a heat-proof surface.
If you are in a shared workspace, write the words "Careful:
HOT" on a piece of paper next to it.
Leave it to cool to room temperature before using.
This can take several minutes.
About the Author
Jessica Adams
Creates helpful guides on hobbies to inspire and educate readers.
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