Low quality solder makes soldering tremendously harder. If you have trouble soldering, it could be due to the low quality solder you’re using. Invest in some good quality lead solder will immediately improve your soldering quality and experience.
New to soldering? I will show you all the basic soldering techniques in this tutorial.
Wondering what solder to buy? Check out my solder recommendations.
Do Not Buy Unknown Solder on eBay
One time, I had 2 quads urgently needed to be built for a coming race, but I was out of solder. So I rushed to picked up some solder on eBay, two unknown brands I never heard of. Although both claimed to be 60/40 lead solder, they turned out to be garbage and gave me terrible results.
I was working on Betaflight F3 AIO and Kakute F4 AIO boards, both have integrated PDB. When I was trying to solder the XT60 pigtail to the solder pads on the FC, the solder took a very long time to melt after applying heat to the joint (15+ seconds at 400°C). It was a massive PITA.
I knew it was something wrong with the solder I bought. So I borrow some brand-name 60/40 lead solder from a friend that day, and the difference was day and night. The solder on the same joint melts right away within a few seconds.
I’ve heard many complaints about how difficult these AIO boards are to work with. They usually point their fingers at the large volume of copper in the board. They are partly correct, the large amount of copper requires more heat for soldering. But the real issue for most could have been the low quality solder they are using (or simply lead-free solder).
Further Reading: Here is a list of tools for building quadcopters, and other tips and tricks in building.
Good Solder and Bad Solder Differences
Bad quality lead solder with too much impurity behaves a bit like Lead-free solder, and good quality lead solder is better because:
- it melts at lower temperature than lead-free or low quality solder
- it solidifies much quicker after heat is removed
All these mean quality lead solder is easier to work with, especially with large gauge wires or PDB where a lot of heat is required.
How to Tell Good Quality Lead Solder
Firstly, look at the solder after it’s been melted and cooled down. Solder with lead looks shinier while the lead-free or low quality lead solder looks dull and matte.
On the left, good quality lead solder; On the right, low quality crap
The second way is by checking the melting temperature. What I normally do is setting the soldering iron at around 240°C (464°F) and see if the solder melts nicely.
Normally, 60/40 (tin/lead) solder should just melt right away. Lead-free or lead solder with too much impurity would turn into something pasty and doesn’t turn into liquid completely.
Good 63/37 solder melts at even lower temperate at about 230°C.
If you have experience with any good quality solder, you should be able to notice the difference immediately :)
Solder Recommendation
If you are buying randomly branded solder on the internet, chances are it’s crappy and purely a waste of money and time. You wouldn’t be able to tell if you are getting the real deal until it arrives on your desk.
The types of lead solder I have been using are 63/37 and Sn60/Pb40.
I strongly recommend getting brand names from a trusted seller. The two brands I personally use and would recommend are:
Choices for 63/37:
- Kester 63/37: https://amzn.to/32hj3Oc
- MG Chemical 63/37: https://amzn.to/3h2x5XR
Choices for 60/40:
- Kester 60/40: https://amzn.to/2ZtASrr
- MG Chemical 60/40: https://amzn.to/2C9FOc9
Apart from Amazon, you can also try your local hardware store. And avoid getting solder from Banggood at all cost!
Edit History
- Jul 2017 – Article created
- Apr 2018 – Updated “Solder Recommendation”
13 comments
and remember to keep a flow of air through your work area to take the fumes away from you.
Lead poisoning is accumulative and insidious.
Otherwise more great info! Thanks Oscar, always informative and real. (low hype content) :)
Sure the links are pointing at the correct products? :-|
Weird, Amazon is redirecting to the wrong products. I have updated the links now.
What’s so bad about lead free solder? I have honestly never had any of these problems with high quality lead free solder. While yes, I agree that lead solder is more “idiot proof” if you have an iron at the correct temperature and you have a good habbit of heating the work, not the solder, then u should not have any problems with lead free aolder.
Yes, lead-free solder sucks!!!! I recently mentored a student UAV competition, the rulemakers insisted on using lead free solder. What a pain it was watching people try to use it, even with flux, several pads were lifted due to excessive heat. I had to repair the damage done.
I like 60/40 Kester but I’ve found the Kester 63/37 lead solder to be even better. Its Eutetic which means it melts and solidifies at one temperature. It’s much less sensitive to pasty, cold solder joints due to movements during cooling, it also has a lower melting point than 60/40. NASA only uses 63/37, that says something right there. The only downside is its slightly more expensive.
Yes I got 3 rolls of “JJS” 63/37 from Banggood and it’s pure garbage… it’s lead solder but it make the solder iron tip filthy as it needs too much heat to work with and might as well use wire to solder with as it doesn’t melt well. However Sparkfun’s “Special Blend” unleaded solder with silver is IMO the best solder to use on RC aircraft as first it’s much lighter in weight and just as easy to use a leaded solder even when 3 years out of date (water based flux), and it melts in really well with other unleaded solders you end up having to mix your solder with where leaded solder has to get too hot (flux burns) to match melt temp of factory unleaded solder and you risk a cold solder joint. The only downside of Sparkfun SB is it’s shelf life is only a year I believe due to using water based flux (but just used up the last of some 3-4 yr old SSB and it still worked well), and mostly it’s more expensive than most leaded solder.
I’m from EU and from my knowledge only lead-free can be sold here. I bought from BG what I think it has Pb and I’m happy with it, seems like it’s Pb type and not lead-free.
Bogdan, that’s not true. You can’t sell products made using leaded solder, but you can sell leaded solder.
Bruce @ RC Model reviews put is nicely once(he did a video on a similar topic). The amount of lead you are using is miniscule compared to what a manufacture would be using in a single day of board making. Let them use lead free with their expensive manufacturing soldering equipment.
Lead free is better for health, actually all the industry use leadfree, but OK it’s Holly shit to sold compared to 60/40 , use Metcal or OKI magnetic soldering iron with lead free for better temperature transfert included big GND copper so wonderful compared to standard resistive soldering iron
I don’t think that these crappy solders are actually lead-free (as those tend to be more expensive than lead-based ones), but they aren’t anywhere 60/40 either. Probably they have much less tin than it should be.
Kester 44 is my personal go-to. It’s the same as the one you posted the link to, except it’s also rosin core, which also helps a little. 0.20 is about the perfect diameter for the stuff we solder typically. For something like an XT60 you’ll need to use a longer length but it won’t be so big you can’t feed it into little solder pad joints. A 1-pound spool ($25-$30) should last you an eternity, and with Amazon Prime you’ll have it the day after tomorrow. Forget that lead-free sh!t off eBay!
Yea you are right Kester 44 is better indeed, updated the link now!