The 3 Best Soldering Irons

There are four main reasons that I find people struggle with soldering.

Firstly, may people have never actually been taught how to make a proper joint and so end up putting solder onto the end of the iron and then applying this to the part they want to solder. This burns off the flux (which cleans the surfaces as you solder) rendering it useless when you actually come to make the joint. As normal, Dave Jones has an excellent video on this – check out his video, which is actually part two of a very thorough three-part series on the subject. If you want to skip straight to the part of this video where he actually makes a joint, it’s at about 3:30 in – but I would strongly recommend watching the whole video (and the others in his series).

Secondly, people often use lead-free solder in their projects when there’s no need to. Lead-free solder is a more difficult material to work with than traditional leaded solder, as the melting characteristics are less favourable. Provided that you wash your hands after working with leaded solder, it is just as safe to work with as lead-free, so always purchase leaded solder for your projects. You should also make sure that solder is specified as “no-clean” – this means that the flux inside the solder does not require removal from the board after the joint has been made. Some fluxes are very aggressive and if left in place and not cleaned off they will corrode your tracks over time, leaving you with a broken project! No-clean flux (and by extension no-clean solder) is specifically designed not to do this.

Metcal MX-500P-11

This is my old trusty iron, which has done ten years of service on my workbench and probably another ten or so with the person I bought it from. In my opinion, Metcal (who were acquired by OKI in 1996, which still feels recent to me) make the best soldering irons out there. The main reason for this is that they have very efficient thermal coupling between the control system and the part being soldered, which means fast heat-up time (mine takes around eight seconds) and no overshoot (where the temperature temporarily gets too high) because of a material-based temperature control system. You’re not going to see a variable temperature control on Metcal or OKI stuff – because it’s not required. Metcal irons have specific tips for specific temperatures, which sounds confusing, but actually, the standard tips work out great for both leaded and lead-free solder and you only need to change tips if you’re working with very specific solder types (like indium-based low-temperature solder on sensitive parts). These are expensive systems, but again eBay frequently has older second-hand systems for sale (which are compatible with newer parts). If your idea of “treat yo’ self” involves buying hand tools for electronics, you know what to do.

Hakko 808-KIT/P (now replaced by Hakko FR300-05/P)

So this is the black sheep of this post – I’m meant to be writing about soldering, but this is a desoldering gun! A few years back I had someone come to me with a project where a lot of through-hole components had to be replaced on a set of boards. With the timescale they had in mind, getting an external company to do the rework wasn’t on the cards, so I set about purchasing a desoldering gun. I mostly chose this because I could get it in a hurry and it got reasonable reviews on the web. One thing to note is that the gun has the vacuum pump built into the tool, which makes it much heavier than a more conventional system where this is part of a desk-based unit and the tool itself is quite light. However, this was just about acceptable for the 5000 or so joints that needed removing. It definitely built up my wrist strength! I think that if I were doing a lot of through-hole rework I would probably go for a second-hand system with a separate vacuum pump, but for the project, we worked on this was sufficient unto the day.

Ideal-Tek tweezers

Bonus-round! I know this is all about soldering irons, but having decent tweezers makes surface mount work so much easier. I’ve used lots of rubbish ones in the past and it’s infuriating when the tweezers don’t align or they stick to the tiny part you are working with or break or all three. Ideal-Tek seems to be a good compromise between cost and performance. My favourite all-rounder is the SM106, but there’s a tweezer there for pretty much every job. Once you get a good pair, I can guarantee you won’t be lending them out.

That’s it for this post – as normal I can’t stick to the topic and managed to talk about three soldering irons and three things that are not soldering irons. Hopefully, there’s something on the list that’s right for you. One thing I would be really interested in hearing is if anyone out there knows of a decent soldering iron for £100 or less (since that’s roughly what a Hakko FX-888D costs). I would love to hear your opinions, so feel free to comment on Twitter.