Experiment 12: Joining Two Wires Together
108 Chapter 3
Your Second Solder Joint
Time now to try your pencil-style soldering iron. Once again, you must leave it
plugged in for a good five minutes to make sure it’s hot enough. In the mean-
time, don’t forget to unplug your other soldering iron, and put it somewhere
safe while it cools.
This time I’d like you to align the wires parallel with each other. Joining them
this way is a little more difficult than joining them when they cross each other,
but it’s a necessary skill. Otherwise, you won’t be able to slide heat-shrink tub-
ing over the finished joint to insulate it.
Figures 3-40 through 3-44 show a successful joint of this type. The two wires
do not have to make perfect contact with each other; the solder will fill any
small gaps. But the wires must be hot enough for the solder to flow, and this
can take an extra few seconds when you use the low-wattage pencil-style iron.
Be sure to feed the solder in as shown in the pictures. Remember: don’t try
to carry the solder to the joint on the tip of the iron. Heat the wires first, and
then touch the solder to the wires and the tip of the iron, while keeping it in
contact with the wires. Wait until the solder liquifies, and you will see it run-
ning eagerly into the joint. If this doesn’t happen, be more patient and apply
the heat for a little longer.Figure 3-40 Figure 3-41 Figure 3-42
Figure 3-43. This and the preceding three
figures show how joining two wires that
are parallel is more difficult, and the
low-wattage, pencil-type soldering iron will
require longer to heat them sufficiently for
a good joint. Thinner solder can be used.Figure 3-44. The finished joint has enough
solder for strength, but not so much solder
that it will prevent heat-shrink tubing from
sliding over it.