“How do I maintain
my soldering iron? I see so many different methods online that I find it
confusing.”
Regular
cleaning
There at least two reasons for regular cleaning of the
solder bit.
The first is to avoid the build-up of carbon and other
contaminants which impedes the transfer of heat from the soldering bit to the
solder and surfaces to be joined.
Many soldering stations come with
a sponge which, when wet, is used to quickly swipe the iron's tip clean. A
small amount of fresh solder is usually then applied to the clean tip in a
process called tinning.
The second is to maintain the
soldering bit in good condition.
The copper that forms the
heat-conducting bulk of the soldering iron's tip will dissolve into the molten
solder, slowly eroding the tip if it is not properly cleaned. As a result of
this, most soldering iron tips are plated to resist wearing down under use. To
avoid damaging the plating, abrasives such as sand paper or wire brushes should
not be used to clean them. Tips without this plating or where the plating has
been broken-through may need to be periodically sanded or filed to keep them
smooth.
To avoid using abrasives,
cleaning with sal ammoniac is recommended. This comes in a
block. You rub the hot soldering iron bit on the surface. As the surface
becomes hot, it begins the cleaning process, noted by the smoke rising from the
block. When the block under the bit becomes clear, the bit will be clean and
can be tinned as above. If this is done at the end of each session of
soldering, the bit will last longer and will be ready for soldering immediately
when you next need to use it.
Turn
off the Iron
The most important element in the
deterioration of soldering iron bits is long idle times. This is where you
leave the iron on, and not in use, for a long time.
Have
everything ready when you start soldering, so the iron will be used
continuously, and will not sit there building up heat, while you get ready to
use it again. An idle iron will keep heating to its maximum capacity and,
without anything to transfer the heat to, it will start burning off the tinning
after a short while. If you will not be using the iron for a while turn it off
until you are ready again.
Tinning
If a bit has not been properly
tinned, solder will not wet to it. Without solder on the bit heat transfer from
the bit to the work surface may become extremely difficult and time consuming,
or even impossible.
You will understand that proper
wiping and continuous wetting is important and a lot easier than continually
having to clean and re-tin the bit, especially at the risk of damage to the
plated surface because of accidentally scratching, or over abrading it.
When you notice that an iron is
not performing as well as it did when it was new you will find that poor
thermal transfer from the element to the work is usually the cause. Improper
care and maintenance and the lack of a periodic cleaning of the bit can cause a
layer of oxides to form, which will inhibit the transfer of heat through the
bit.
These factors are reasons why
keeping a film of solder on the bit (tinning) is important in maintaining the
long life of the soldering bit.
Cleaning
the whole Bit.
Each soldering bit has a shank which fits into a heating
collar of one kind or another. The bit
should be removed at periodic intervals and the build-up of oxides should be
cleaned from the shank. The oxides
inhibit the transfer of heat from the elements to the soldering bit. This cleaning work, of course should be done
when the iron is cool. You can use fine
abrasives on the shank to remove the oxides.
You can also make a tube of fine sand paper to clean the inside of the
heating collar. This should not be done
on ceramic heated soldering irons such as the Hakko.
Wattage
Another element in the maintenance of soldering irons is
to have an iron of high enough wattage to readily
melt the solder and be able to reheat fast enough to maintain the necessary
melting temperature. An iron with enough power will reduce the strain on the
heating element of the iron and the strain on the user while waiting for the
iron to catch up.
For example, an 80-watt iron is
sufficient to solder with, but it will continue to get hotter, as it has no
temperature control until it becomes too hot for stained glass soldering, often
causing breaks in the glass. An iron of this type is often used with a rheostat
in order to prevent overheating while it is idling. However, this reduces the
power to the iron and so increases the time needed to recover sufficient heat
to continue soldering. Also, a rheostat
only slows the heat up, it does not limit it, so eventually the iron will still
become too hot if left to idle.
Most temperature-controlled irons
seem to be produced in 100 watts or higher. These irons attempt to maintain a
constant temperature. Their ability to do so depends on the wattage and the
amount of heat drained from the bit during soldering. The temperature-controlled
irons are normally supplied with a 700°F bit (identified by the number 7
stamped on the internal end of the bit) and is sufficient to melt solder
without long recovery times. You can obtain bits of different temperature
ratings, commonly 800°F and 600°F. The 800°F bit is particularly useful when
doing a lot of copper foil soldering, because it recovers to a higher
temperature, allowing much more continuous soldering action.
You can also get several sizes of
tips for different detail of work. Upon
first sight a fine tip would be useful for fine copper foil work.
But fine tips loose heat quickly,
requiring the user to wait while the tip regains the required heat. A 6mm to 8mm wide bit is useful to maintain
the heat during the running of a long bead.
Of course, the bit is wider than the bead being run, but the solder has
enough surface tension, while molten, to draw up into a bead the copper foil
without spreading – unless too much solder is being applied. Really big bits of
12mm or larger are not practical – long initial heat up times, and too much
area is covered, even though there is enough heat stored for really long solder
beads.
