Your Iron
This
is the key to soldering: you need to use a good soldering iron.
First off, anything from Radio Shack is complete crap. I cannot
stress this enough. Radio Shack sells the world's worst soldering
irons. They are poorly constructed, do not transfer heat well,
and are made with shoddy metals that wear out very quickly.
Given the choice between a Radio Shack iron and a Bic lighter,
I'd take the Bic lighter. This is a shame since so many people
fail at soldering because they start out with a Radio Shack
iron. So the first rule of Solder Club is: never buy a Radio
Shack Iron.
Another important note: Don't use a soldering gun. These
are too hot and too clumsy for electronics work.
The good news is that there plenty of good, inexpensive soldering
irons out there. Before looking at specific models, let's identify
the key soldering iron characteristics.
- Form Factor: The most common beginner form factor
is a pencil iron. The pencil iron is simply a handle, heating
element, tip, and cord all in one unit. These are generally
inexpensive, and you would purchase a separate stand and
cleaner. A more convenient and easy-to-use form factor is
the soldering station. In this configuration, the pencil
plugs into a base unit, and the base unit usually has some
type of temperature control. Soldering stations also include
a separate stand with some type of integrated cleaner. Recommendations
here will focus on soldering stations.
- Wattage: A soldering iron's wattage does not
correlate to how hot it will get. Rather, it defines how
quickly the soldering iron will recover from heat loss caused
by contact between the soldering iron tip and other surfaces.
Low-wattage irons will take longer to heat back up after
losing heat. Larger wattage irons will recover quickly.
In general, I like to use irons in the 40-80 watt range.
- Temperature Control: A good soldering station
will have built-in electronic temperature control. This
is achieved by incorporating a thermostat circuit. Dial
in your temperature and the iron will work to keep itself
as close to that temperature as possible.
With the basic list of characteristics under our belt, let's
look at some options:
Good:
Circuit Specialists Stations
This unit is incredible bang for the buck action. I've used
this myself for many years. At around $40, it is a great value
in an adjustable temp soldering iron. It includes a metal stand
that also holds a cleaning sponge.
Circuit Specialists has a wide selection of irons, and some
great money-saving bundles as well. They also carry a wide range
of replacement tips, solder and other consumables for your soldering
pleasure.
Check them out:
http://www.circuitspecialists.com/level.itml/icOid/6388
Better: Weller Soldering Irons and Soldering Stations
Weller has been consistently making some of the best soldering
gear since the beginning of time. You pay more for a Weller,
but it will last a lifetime of properly cared for.
An excellent choice in the Weller line is the WES51 Analog
Soldering Station. It is a 50 watt iron with electronic temperature
control .
Note that many Weller soldering stations do not come with
a soldering tip (which is whack as far as I'm concerned). A
good general purpose tip for the kind of through-hole soldering
you'll be doing is the Weller ETO 1/32"long Conical(eto) Weller
Et-series.
You can get great prices on Weller gear at online tool sites
or at Amazon.com:
http://www.amazon.com/Weller-WES51-Analog-Soldering-Station/dp/B000BRC2XU
Best:
Hakko Irons
As far as I'm concerned, Japanese-based Hakko offers some
of the best engineering when it comes to soldering stations.
They sit at the higher end of the price scale, but are well
worth it.
I currently use the
Hakko 936 soldering station and it is rock solid and well
made.
If money is no object, you can end up spending thousands
of dollars on Hakko gear!
Consumables
For
solder, you want 60/40 Tin/Lead mix, rosin flux core. The thickness
or diameter of the solder should be in the range of 1mm to 1.5mm.
Anything bigger or smaller will make soldering tougher. Do not
use plumber solder or any type of acid-core, you'll make a mess
and probably go blind.
Other useful consumables include:
- Replacement cleaning sponges or,
- wire wool cleaners
- De-soldering braid
Soldering Technique
Proper soldering technique can be distilled down to a basic
sequence of operations.
- Turn on your soldering iron and let it reach
the desired operating temperature.
- Clean the tip using either a damp sponge cleaner
or a brass wire mesh cleaner.
- Tin the tip by applying a small amount of solder.
You don't want a big glob on the end, just a thin film coating.
- Apply heat to the part to be soldered.
- Apply solder: Once the part is heated, apply
a small amount of solder while the iron tip is still on
the part.
- Observe the solder joint: as soon as the solder
flows cleanly and forms a non-flaky shiny bond, remove the
iron.
- Place the iron back in its stand.
- For additional solder joints, return to step 2.
This sounds rather simple, and once you get the hang of it,
it really is. Remember to clean your tip just before you use
it, not after. The other key is to heat the parts first, then
apply the solder.
Common Soldering Tasks, Illustrated
Figure 1: Connecting two wires
Figure 2: Board-mounting a component
Figure 3: Ideal solder amount
Hints and Tricks
Here are some useful tips for a more enjoyable soldering
experience.
- Temperature: A soldering iron tip of between 800 and
900 degrees Fahrenheit is ideal for electronics soldering.
- Do not solder while wearing shorts.
- If your soldering iron should start to fall from your
work surface, do not attempt to catch it. Let it hit the
ground, then go after it.
- Don't solder transistors, integrated circuits, or very
expensive parts to a PCB. Instead, solder in a socket. This
will save you many incidents of frustration over the long
run. (i.e. there is nothing more frustrating than looking
at a soldered-in backwards transistor or integrated circuit
:))
- Take your time, your soldering will be better for it.
- Don't try to re-surface your tip with sandpaper or filing.
That will just grind off the coating that makes the tip
solder well. If your tip won't clean or re-tin, get a new
tip.
Safety
No soldering how-to article would be complete without a discussion
of the safety.
- Stuff can leap off your iron right into you one good
eye. Wear eye protection!
- Nasty ass fumes that are spewed about when you solder.
You should always solder in a well-ventilated area, and
away from children or pets. It is also a wise investment
to acquire a fume extractor. The fume extractor is a device
which uses a fan to pull air from immediately around your
soldering area through a filter, thereby severely reducing
the amount of noxious compounds put off by melting solder
and rosin. If you don't have a fume extractor, you should
at least use a fan to blow any smoke or vapors away from
your soldering area.
Have fun soldering.
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