KABTRONICS World Clock, Operating And Assembly Manual

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K A B T R O N I C S S O L D E R I N G
World Clock Kit Page 6
A good solder joint will form a shiny curved surface bonding the lead and the pad on the PC
board. If the lead wasn’t heated enough to melt the solder, the solder will wick in to the pad, but
will not adhere to the lead. You may notice a dark line around the lead where the solder dives
down through the hole.
A similar bad joint forms when the pad wasn’t heated enough to melt the solder. A cold solder
joint can often be fixed by reheating the joint; sometime a little more solder will be needed.
More detailed instructions can be found on the internet with a little searching on the topic of
soldering.
After inspecting the solder joint, clip off the excess lead using the diagonal cutter. Cut at the top
of the solder joint; don’t dig into the solder joint.
Unsoldering
A supply of de-soldering braid is supplied with the kit. If you find the need to remove a
component, use the de-solder braid by pulling out a few inches and pressing the braid against the
lead and the pad using the iron. You will see the solder melt and spread into the wick leaving very
little solder left in the pad.
Sometimes it helps to clip the lead off the component so you can deal with each lead separately.
Optional Clean-up
The clear sticky rosin left around the solder site can be cleaned up with alcohol and a toothbrush,
but be sure to let the board dry before expecting the board to operate properly. You won’t hurt
the circuit by powering it up, but it won’t count right until the board has completely dried. Water
soluble rosin-cored solder is available at hobby stores. As for me, I don’t bother to clean up the
board unless the counters are not working right, then I clean off the rosin.