Hi Bill, I don't often use stretched sprue. When I do, the method I use is to hold the sprue a few inches above the flame rolling it until I feel it get really soft. I then quickly lift it up while sharply pulling the sprue apart. I go through alot of trys to get the length and circumference I need. To be honest, I am not very good at streching sprue; I find it easier to use either wire, evergreen rod, invisible thread, etc, for what I need.
Ernest
