DON’T BUY Low Quality Solder for Building Quadcopters

Low quality solder makes soldering tremendously harder. If you have trouble soldering the reason is most likely to be the solder you use. If you want to have better quadcopter building experience, invest in good quality lead solder!

New to soldering? Please take a look at our guide on buying soldering equipment and the best soldering practices.

Do Not Buy Unknown Solder on Ebay

One time, I had 2 quads I urgently need to build for a coming race, but I ran out of solder. Due to the time constraint, I randomly picked up some solder from eBay, two random brands I’d never heard of. Although both claimed to be 60/40 lead solder, they turned out to be total garbage and gave me terrible result.

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 hardly melt after applying heat the joint for 10+ seconds at 400°C (752°F). 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, and the difference was day and night. The solder on the same joint melts right away within 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 big amount of copper requires more heat for soldering. But the real issue for most could have been the low quality solder they are using with too much impurity in it.

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:

Choices for 60/40:

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”

10 thoughts on “DON’T BUY Low Quality Solder for Building Quadcopters

  1. Rabbi Shekelstein

    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.

    Reply
  2. Chris Barth

    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.

    Reply
  3. John Hendry

    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.

    Reply
  4. Bogdan

    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.

    Reply
  5. Brendon

    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.

    Reply
  6. Jackantubis

    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

    Reply
  7. DuMOHsmol

    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.

    Reply
  8. SwissFreek

    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!

    Reply

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