USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 2/TASK 1
(c) As soon as the temperature has risen sufficiently, the solder
will spread smoothly and evenly over the faces.
The purpose of this
procedure is to do the tinning as soon as the copper is hot enough to melt
the solder and before it has had a chance to oxidize.
(d) When the tinning is completed, wipe the tip with a rag while
the solder is hot and molten. This will expose an even, almost mirror-like
layer of molten solder on the tip faces.
NOTE
If the iron is large, either acid core or rosin core
solder may be used.
Small irons used for soldering
electrical parts and wiring should be tinned only with
rosin core solder or solid solder and rosin.
(2) Regulating Temperature of Electric Soldering Iron.
Electric
soldering irons are designed for continued use.
Once connected, they
develop heat so rapidly that the tip becomes overheated and oxidized,
corroding rapidly if the iron is not used constantly.
It is often
convenient to have a hot iron ready for use without having to wait to heat
it up. This can be done by connecting the iron in series with a light bulb
and a switch, as shown in figure 59 on the following page. The resistance
of the lamp reduces the amount of current flowing through the iron, thereby
preventing it from developing its maximum temperature. When the switch is
open so that the current flows through both the iron and the lamp in series,
the iron may be left connected to the power line with no danger of
overheating. When the iron is to be used, close the switch to short circuit
out the lamp. This increases the current flowing through the iron to its
normal value, permitting it to develop maximum heat. The size of the lamp
will depend upon the size of the iron and the desired temperature while
waiting and will have to be determined by experiment. It should be rated
(number of watts rating) to permit the flow of that amount of current which
is required to keep the iron just hot enough to melt solder, or somewhat
below that temperature, if desired.
77
Previous Page
