Be Aware of Fake and Low Quality Lead Solder for building quadcopter

Are you having trouble soldering? Check your solder! Good quality lead solder makes soldering a lot easier, and the issue you are having is normally due to the low quality or lead-free solder you are using.

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

Here is the story that triggered me to write this blog post.

Recently I picked up two different, unknown solder from EBay, claimed to be 60/40 lead solder, but both turned out to be total garbage and gave me terrible result.

I was working on my 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, these solders wouldn’t even melt after heating the joint for 10+ seconds at 400°C (752°F). It was a massive PITA.

After obtaining some brand-name 60/40 lead solder, it was a day-night difference – the solder on the same joint melts right away after in about 3 seconds.

Many complain about these AIO boards are difficult to solder, I think the problem could just be the low quality solder with too much impurities in it.

Check out this list of tools for building quadcopters, and other tips and tricks in building quadcopters.

Differences between good and bad lead solder

Bad quality solder with too much impurity performs a bit like Lead-free solder:

  • Good quality lead solder melts at lower temperature than lead-free or low quality solder
  • Good quality lead solder solidify 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 if I have good quality lead solder?

Firstly, look at the solder after it’s been melted and cooled down. Solder with lead looks a bit shinier while the lead-free or low quality solder looks dull and matte.

On the left, good quality lead solder; On the right, lead free, or possibly low quality lead solder

Second way to check is the melting temperature. What I normally do is setting the soldering iron at around 240°C (464°F) and try to melt the solder directly.

60/40 (tin/lead) solder would melt right away, while lead-free solder would turn into something pasty and doesn’t liquefy completely.

Good 63/37 solder melts at even lower temperate (about 230°C).

Anyway if you have ever used any good quality solder, you should be able to notice the difference immediately :)

Solder Recommendation

If you are buying randomly branded solder from the internet, the chances are it could be crappy and purely 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 type of lead solder I have been using are 63/37 and Sn60/Pb40.

I strongly recommend getting a brand name from trusted seller. The two brands I’ve personally used and would recommend are:

First choices: (63/37):

Second choices (60/40):

Apart from Amazon, you can also try your local hardware store. Avoid getting solder from Banggood at all cost!

9 thoughts on “Be Aware of Fake and Low Quality Lead Solder for building quadcopter

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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!


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