Today I made perhaps my fifth attempt at making my own Philosophical Egg - this is basically a small flask with a really long neck. I tried making one out of pyrex glass tubing, and test tubes. All failed because a small hole would pop its way through. I really think it's my torch, that it's not strong enough. I'm using a propane torch, whereas glassblowers typically use oxy-acetylene torches (they cost about $400, which I don't have). I've read online that you can use propane, but it's very limiting. I think there's one website that sells special torch heads for propane tanks geared for glass blowing, so I might try that.
Why don't you just use Kjeldahl flasks? They look very much like the old flasks that alchemists used for "digestion" operations:
ReplyDeletehttp://www.canfortlab.com/pic/big/512_0.jpg
PS: propane is certainly hot enough to work glass, even more so with oxygen injection. In fact, if you are not careful, it will just melt the glass!