How to Make a Minitorch

One thing I needed to do was to simultaneously cut and seal a capillary accurately to a predefined length, using a minitorch with an approximately 2 or 3 mm flame as cutting tool. 
This is how I made the minitorch:
1.  Light a Bunsen burner. Attach a glass capillary to a second gas line, and light the gas flowing out of the tip of the capillary.
2.  Bring the tip of the capillary carefully to the side of the hot zone of the Bunsen burner flame, so that it begins to melt the tip of the capillary (noticeable in that the flame flowing past the contact area acquires a yellow colouring). The melting of the tip causes the passage through the capillary tip to constrict. When this happens too fast, the capillary tip closes completely.
3.  With a bit of practice, the melting of the tip can be stopped just before complete closure, so that a minimal channel remains, allowing for a minimal stream of gas to burn in a miniflame.

© Waruno Mahdi 1979, 1998, 2000