Soldering Irons
Soldering Irons
After years of novice fumbling about, I have learned to respect the need for the "right tool for the job." This applies to soldering irons just as well as any other tool. One size does not fit all and you get what you pay for. I was almost turned away from electronics as a young kid because soldering was hard . In hindsight, I now understand that a woodburning iron and acid core solder are the wrong tools for electronics work ;)
Types
* Pencil - These are called pencil soldering irons because... well, they look roughly like a pencil. For most electronics work, you'll use an iron with a pencil grip, whether it's a stand-alone (plugs directly into an electrical outlet) iron or part of a soldering station. Common stand-alone irons come in 15 to 40 Watt ratings. A 30 Watt, stand-alone pencil grip soldering iron is a good compromise for a person who solders only occasionally.
* Soldering Station - A soldering station includes a pencil grip iron that is attached to another unit (the station) that has at least some means of controlling the temperature at the tip. The simplest stations just allow one to vary the power delivered to the tip. More advanced (and more expensive) soldering stations have a temperature sensor near the tip that provides feedback to control the tip temperature more accurately. For the more serious electronics hobbiest, I would recommend a low, to mid-priced soldering station over a stand-alone iron. If you plan to solder often, a better, temperature controlled station will pay for itself in reliability and lack of frustration.
* Soldering 'Gun' - Solder guns are so called because of their gun shape and grip. These are not useful for soldering on PCBs (except maybe in very limited cases for high current carrying connections). These have two terminals connected to the secondary windings of a transformer; the tip is at the junction of two pieces of copper that are connected to those terminals. Soldering guns are useful when a lot of heat is needed, such as when making splices between large conductors or connecting a wire to a large terminal. Be careful to observe the limited duty cycle of soldering guns; the transformer may burn out if not allowed to cool often.
* Portable - Portable soldering irons have no wires to rein you in. They can be very handy when wall-power is not available or when cords would get in the way. Portable irons come in two general varieties: battery powered and butane powered. In my experience, a nice soldering station can't be beat for quality of solder job and ease of use, but when portability is key, I would choose a butane powered iron first and battery powered second. Battery powered irons are more limited by their available charge and their charging stations tend to overcharge them, shortening the useful battery life.
* 'Cold Heat' - This is a relatively new type of iron whose tip is made of two, small electrodes in a kind of fork shape. Solder and the workpiece are heated when the tip is placed in contact with them and current flows between the electrodes in a sort of short-circuit. These can be very handy for the occasional odd-job. They "heat" quickly but don't pose as much risk of causing burns or fires as traditional irons. However, since electrical current does flow between the electrodes, caution should be used to prevent current from being passed between leads on devices (ICs, other active components) you might solder as that could destroy the device. It is also my opinion that a traditional, fine tipped iron is much more versatile and intuitive to use.
Tips (the working end of the iron)
* Plain Copper - The cheapest tips are made of plain copper. From personal experience, I strongly recommend you never waste your time or money with these unless you must solder something now and nothing else is available. These tips erode quickly with use; corrosion of these tips occurs continuously while heated and being used, causing poor wetting and heat transfer.
* Plated - Common good tips are electroplated entirely with iron to inhibit corrosion in general and plated with a layer of nickel at the working/wettable end. Some are plated with chrome to prevent wetting (solder sticking to it) on the non-working areas of the tip. Note that corrosion will still occur and tips will need to be replaced as needed... keep extras on-hand.
Caring for your iron
* Don't leave your iron or soldering station sitting idle but heated for long periods. This allows the tip more opportunity to corrode and uses up the life of the heating element unnecessarily.
* Clean the tip frequently (on a wet sponge) while soldering, but wet the tip fully with solder anytime it's heated but sitting idle and when you've finished your work and are about to switch off the iron. This helps prevent corrosion of the tip.
* Do not attempt to file or otherwise shape a good tip; this will damage the plating.
* Be sure your soldering station or holder is firmly positioned on a flat, clean workspace; they don't survive very many drops to the floor.
* Do not use a soldering iron where children or animals might come into contact with them.