Bob,
I use the flame to heat the inside of the tip, once the inside of the tip is red hot I shut off the flame and just use the butane to keep it hot. I dont know if you can see it but theres a round knob just before the tip that slides back to shut the butane off for a split second.
I dont heat my rails, the solder on the tip is hot enough heat the flux up to make a good "weld" between the rail and the wire.
It is a small scale version of a plumbers torch, When you heat up a pipe your only heating it to get the flux hot enough to draw the solder into the joint.
I use the flame to heat the inside of the tip, once the inside of the tip is red hot I shut off the flame and just use the butane to keep it hot. I dont know if you can see it but theres a round knob just before the tip that slides back to shut the butane off for a split second.
I dont heat my rails, the solder on the tip is hot enough heat the flux up to make a good "weld" between the rail and the wire.
It is a small scale version of a plumbers torch, When you heat up a pipe your only heating it to get the flux hot enough to draw the solder into the joint.