This guide is intended for beginner/intermediate level solderers (although I will cover some advanced topics at the end). Since soldering is part art and part science you will find that everyone has their own personal technique and equipment preferences. The solutions I present here will provide the fastest/easiest/safest way to get good results, and over time as your skill level improves you can adapt the techniques to what works best for you.
I will break the information into three categories; basic, intermediate and advanced. The basic category will cover playfield work, like replacing a diode, lamp or solenoid, the intermediate category will focus on board repair and the advanced category will cover specific advanced board repair techniques like through-hole repair.
In part 1 we'll discuss soldering/desoldering equipment. In part 2 I'll cover basic (playfield) soldering/desoldering, in part 3 intermediate soldering/desoldering (circuit board), in part 4 advanced board repair techniques.
The most important thing to know when looking at soldering equipment is that it is not like a wrench set, for example. While a cheap wrench set from Harbor Freight will perform the same as an expensive set, at least initially, there is a vast performance difference between cheap soldering equipment and quality products. On the other hand, beginner/intermediate level solderers aren't going to spend several hundred to a few thousand dollars on JBC, Pace or Metcal so I've attempted to provide high performance, but cost-effective solutions.
In the image below you can see the difference in actual temperature at the joint of the Hakko FX-600, with improved tips, versus their older 933 model. In both cases the iron is set for 350°C, yet the FX-600 averages about 280°C at the joint and the 933 about 250°C. The difference is much larger when comparing a good iron to a cheap one.
Cheap soldering equipment is the number one cause of frustration when people are learning how to solder, so spend the extra money and buy quality tools.
Even if you plan on moving on to board repair I would still suggest you purchase a soldering iron since they are a lot easier to use when working under the playfield. You want a 25 watt iron--nothing higher is needed--from a quality manufacturer like Weller or Hakko. The tip is as important as the iron, and this is where those $20 soldering irons really cut corners (tips will be covered in-depth in a later post).
The Weller WP25 Professional costs slightly over $40 on Amazon. It comes with a .125" screwdriver tip (ST3), although I prefer the ST4 tip (.187" screwdriver) since it provides better performance for basic soldering tasks. The additional tip will cost you about $8 on Amazon.
Hakko has discontinued their 25 watt iron that competed with the Weller Pro. They instead now offer a couple of very slick adjustable temperature irons ( FX-600 and FX-601) at a good price (around $70). Both heat up faster and have a faster recovery time than the Weller Pro. My only complaint is the temperature setting on both is in Celsius.
The FX-600 has a temperature range of 392 to 932°F and the FX-601 392 to 1004°F. The FX-600 comes with a conical tip so I suggest you add a .2" chisel tip (T18-S3). The good news is these are the same tips the Hakko FX-888D uses (my recommended temperature controlled soldering station). The FX-601 comes with a .2" screwdriver tip (T19-D5) which is a high thermal capacity tip.
I prefer the FX-600, but some will find the FX-601 easier to work with on playfield soldering since it has a larger heat capacity. Although either could be used for board work in a pinch (the FX-600 the better choice of the two), a temperature controlled soldering station is the recommended solution.