How to Flare Tubing to Hold a Rubber Hose

Secure the tube in a vise while heating its end.

If tubing needs to be connected to a rubber hose of the same diameter in a science experiment, for example, the tubing, if flexible, can be flared by heating it to fit over the end of the rubber tube. Conversely, the hose can also be heated to fit over the tubing. The item that is more flexible is the one that should be heated and slipped over the other, as it will flare and become flexible in a shorter amount of time.

Things You'll Need

• Vise
• Rag
• Tube
• Hose
• Heat gun or hair dryer
• Gloves

Instructions

1. Wrap a rag around the tubing and secure it in a vise in a horizontal position with the tube's end 12 inches from the vise. Note: the rag will be between the vise jaws and the tube.

2. Turn on a hair dryer or heat gun. Heat around the end of the tube on all sides. If using a heat gun, make sure that the tube does not start to melt, but the last two inches of the tube merely flares and softens. Squeeze the end of the tube slightly with a gloved hand to test its flexibility.

3. Push the end of the hose into the inside end of the flared and heated tube to a depth of two inches. If the hose won't enter the tube, heat the tube until becomes more flared and flexible. Wait for the hose to cool down and gain its original shape. By doing so, it will create a tight fit around the hose. Loosen the vise, take out the tube and remove the rag.

Tips & Warnings

• Do not attempt to heat or flare hard plastic tubes like PVC or ABS, as the tube walls will be too thick to flare. Polyethylene pipe is flexible and may be a suitable hose to use.

• Do not use a propane torch to heat the tube as it will melt it and may emit poisonous fumes.

References

• Oxford Plastics, Inc.: A History of Polyethylene Pipe
• Google Products: U.S. Poly 18340 Polyethylene Pipe 1" x 300 Coil