I've been trying to make glass bubble tubes with common household items. I got some old T5 fluorescent tubes and dremeled a scratch at each end and snapped them fairly cleanly before cleaning the phosphor coating out by pushing a wad of paper towel through them with a rod.
Then I closed one end by heating it carefully with a gas blowtorch (starting slowly to avoid cracking) pulled it to close off the end and then allowed it to cool slowly by giving it a lick of flame from time to time. Then I poured in some rock salt and closed the other end by heating and pulling it into a narrow stem.
Alas, my glass working skills are terrible, and I'm not sure fluorescent tubes and blow torches are the ideal tools. It would be handy to have a proper hand held tipping-off torch with two small burners facing each other. It would also be better to have some traditional 10mm neon type glass tubing.

7 thoughts on “My glass-working skills are rubbish.”
  1. Avataaar/Circle Created with python_avatars Phonotical says:

    Acetone boils at 60c I believe, so maybe exposing it to 100+ not the best idea😉

  2. Avataaar/Circle Created with python_avatars Richard T says:

    Could you pop over to a local university on your next trip to the mainland and ask the chaps in the Chemistry department for a hand? They are master glass workers with the right gear … and will likely work for a few pints down at the pub!

  3. Avataaar/Circle Created with python_avatars bneon says:

    i just noticed a tip from someone who suggests putting it in the freezer don't ever try and heat glass that cold its the exact opposite of what you need to do hot glass and cold don't mix believe me try in by all means and see what happens wear glasses glass is sharp when it breaks and it will if you try that method

  4. Avataaar/Circle Created with python_avatars bneon says:

    hi clive not quite sure what your trying to do with various liquids here ? all glass needs to be warmed up slowly don't put it in the flame straight away hold it close and slightly above the flame  after a minute or so or until you couldn't hold the hot bit in your fingers then introduce it to the hottest part of the flame you will see a cone just above the burner head thats the hottest bit seal one end by quickly rotating the tube in the flame when it starts to sag its ready keep rotating the tube and gently pull away while you continue to rotate it  the idea is to keep the glass wall the same thickness all the way round if its not it will crack when it cools .once you have pulled the excess glass away put it back in the flame still rotating it and gently blow into the tube you should be able to form it with your breath only you will end up with a  roundish end ,let it cool ,start doing the same thing on the other end tapering it leaving just enough of a gap on the inside wall to enable you to pore the liquid of your choice you will need to seal it vertically keeping the liquid away from the hot glass heat the glass as before gently pulling as you rotate the burner the glass will collapse in on itself thats why you need to evenly pull it upwards you don't need a vacuum pump that would draw liquid vapor or even the liquid itself up to the hot glass in the case of meths it will catch fire check out some clips on u/tube of neon glass bending there is one if i remember its tecnolux a US glass maker best of luck

  5. Avataaar/Circle Created with python_avatars m8e says:

    Try heating the water to something like 60 (for Acetone) or 70 degrees (for Methanol). should give a more controlled and gentle boil.

    Then you might be able so seal them while they boil. Acetone have a vapour pressure of 1.14 atmospheres at 60 °c. So the pressure shouldn't be a problem.

  6. Avataaar/Circle Created with python_avatars SeanBZA says:

    Grab some long test tubes off fleabay, and rubber bungs for them. That should work better, or just get a long length of soda glass tube ( not quartz unless you have an oxyhydrogen torch) and close the bottom, then put the salt, make the pinch area then let it cool down, put the liquid then put in freezer for a few hours. Then use a proper vacuum pump and pinch it off.

  7. Avataaar/Circle Created with python_avatars rickyreynolds17 says:

    Whoo 1st comment lol

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