This section is from the book "Experimental Glass Blowing For Boys", by Carleton J. Lynde. Also available from Amazon: Experimental Glass Blowing for Boys.
Heat the end of a piece of No. 2 tube until it is red hot, take it out of the flame, hold the flaring wire inside the end, and press outward gently while you revolve the tube (1, fig. 36). Do you find that the end is flared out (2, Fig. 36)?
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2
Fig. 36. Flaring A Tube
 
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