How to Seal Glass Tubing

Sealing the end of a glass tube is the first step in many glass-blowing projects. By sealing the end of the tube, you create a closed space which can be carefully blown into a bubble. A length of glass tube with one or both ends sealed is also a handy stir rod for chemistry labs. When carefully done, creating sealed glass tubing is a quick and easy process.

Things You'll Need

• Heat-resistant gloves
• Safety goggles
• Bunsen burner or blow torch

Instructions

1. Put on heat-resistant gloves and safety goggles.

2. Light the Bunsen burner or torch and adjust the valve until it burns with a quiet blue flame.

3. Hold the length of tubing by both ends and bring the center of the tube into the flame. Keep the tube steady until the glass in the flame becomes soft and pliable.

4. Twist the ends of the tube in opposite directions while pulling them apart.

5. Set the two halves aside on a heat-resistant surface to cool.

Tips & Warnings

• Ordinary soda glass can be easily manipulated using Bunsen burners or hand torches. Heat-resistant laboratory glass such as Pyrex requires an oxy-acetylene torch to reach the required temperatures.

• Hot glass can cause severe burns. Be careful to keep the heated ends of the glass away from skin or flammable materials. Never attempt to heat glassware without safety goggles and heat-resistant gloves.

• Never attempt to heat glass tubing that is already sealed at both ends. Heating sealed glassware could cause it to shatter.

References

• Dale Chihuly's Glass Blowing: Elizabeth Paal and Elizabeth Miller