We're wanting to do some experiments with siphons and were hoping to bend a 50cm piece of glass tubing into a candy cane shape.

In theory, we should be able to bend glass tubing by heating it and applying gentle pressure. According to the instructions we found on line, the trick is:

• be sure to heat the glass uniformly; glass is an awful heat conductor, so heating one area doesn't mean you've heated the area right next to it
• this also means turning it so you get the front and back
• it also means that you want to heat it for quite a while so the inside gets hoot too
• you want to heat the whole area to be bent (so in our case, about 20 cm about 10 cm from one end
• it also means you want to wait a long time afterwards before touching it because it cools slowly
• you want the glass softened but not sagging; since it's so slow to heat and cool it shouldn't be hard to stop when you're good on temperature

We tried doing this–three of us, all wearing goggles; one wearing welding gloves to hold the tube, one rotating the tube and one applying the torch. We kept the torch moving to avoid hot spots, and changing jobs occasionally when we started getting cramps or wanted to do something different.

The glass got quite hot, but never seemed any softer (it sprang back when the person wearing the gloves tried to bend it just as much as it had when it was cold).

Possible reasons:

• although it seems like we tried a very long time, maybe we gave up too early
• maybe we were trying to heat too long of a section
• maybe we were using the wrong kind of glass
• maybe we weren't keeping the hot part of the flame on the tubing well enough (we aren't even agreeing on what part of the flame was hottest).
• maybe it takes more force to bend glass than we were willing to use (we were worried about breaking it)