Where is all the leaded solder wire? Why is everything lead-free now?

Thread Starter

rambomhtri

Joined Nov 9, 2015
574
About 10 years ago I purchased 100g of soldering wire with composition Pb38, Sn60, Cu2, with a flux core, 0.56mm diameter. It's almost all used now after all these years repairing stuff.

Now I am trying to buy the same wire and every single wire is lead free, almost 100% of them have this HIGE banner LEAD-FREE and composition Sn97, Cu3.

The best reviewed one, which is the one that I just bough, is Sn99, Ag0.3, Cu0.7, with flux core.

My first question is... why? Why did they ban it?
I understand that lead is toxic, but not to us who repair stuff under the normal regular repairing conditions and temperatures. May be it's problematic later when disposed. I understand that if you are a company that needs thousands of Kg of soldering wire, "they" make you use lead-free wire. That's a big difference. However, to completely remove it to people who use it to repair, besides not having any meaningful impact, is what I don't understand.

AFAIK, the wire I've been using is amongst the bests to do the job, or the 37/63, and the big problem with lead-free soldering wires is that they require considerably more heat to melt (fake ecofriendly deadheads, that means more electricity wasted, less efficiency), and is simply a way worse wire to work with.

No I am worried I won't be able to perform as good as I was all these years, it's the very first time I try lead-free wire. Also I am kind of angry I can't find any leaded wire, wth.

I was looking in Amazon, but in AliExpress I've found some, however, very cryptic and hidden, it's like they fear to use the word "lead":
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Which one should I buy?
 
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Thread Starter

rambomhtri

Joined Nov 9, 2015
574
I don't see that one in my local Amazon (EU), in AliExpress this one looks fine, right?

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What is better, Sn63 Pb37 or Sn60 Pb38 Cu2?
I have been using the later all my life
 

Externet

Joined Nov 29, 2005
2,237
The EU excomunicated lead maaaany years ago. All electronic equipment entering Europe must be without lead and other heavy metals by law. (But ask me what are the car batteries in Europe made of) Oriental manufacturers of electronics had to pass trough the funnel leadless.
U.S. does not have such mandate.
 

ronsimpson

Joined Oct 7, 2019
3,150
We don't use lead in most things because it causes brain problems. The Romans used lead drinking containers and it really messed them up. We have pulled lead out of fuel (except for airplanes) and the lead in children is way down. Except near airports. I have a 100+ year old rental house and it had lead water pipes from the street. The city came and replaced all the pipes for free. Heavy metals is not a good thing to eat, drink, inhale. It gets into your system and does not leave.
 

dl324

Joined Mar 30, 2015
17,017
What is better, Sn63 Pb37 or Sn60 Pb38 Cu2?
Personally, I think 63/37 is better because it's eutectic. The latter isn't eutectic because the melting temperature is 183-190C.

The last time I researched RoHS, solder with lead was allowed in the EU for hobbyists.
 

crutschow

Joined Mar 14, 2008
34,706
We don't use lead in most things because it causes brain problems.
That's only if it we breath or ingest small particles, or it gets dissolved in our drinking water.
I highly doubt there are very many that have ever had significant lead intake from soldered connections.

The removal of lead in solder was just overreaction by politicians who heard that lead is bad.
It pales in comparison to the 4-5 million tons of lead put into the environment from the use of leaded gasoline since the 1920's until it was banned.
 

Ian0

Joined Aug 7, 2020
10,076
The lead ban came from two studies about lead leaching out from landfill. One which said it did and one which said it didn't.
There were a lot of claims about how products would become less reliable due to tin whiskers on fine pitch devices, but as far as I can see it hasn't happened.
So my recommendation would be to use the lead-free stuff even though it doesn't solder quite as well, especially if you are mending something that has been built with lead-free.
Unlike leaded solder where you can get 60/40 or 63/37 and nothing much else, there are dozens of alloys of lead-free.
The best is TSC (tin silver copper) with about 2.5% silver.
Don't use the 99% tin versions as they can suffer from tin pest.

I work in off-grid power and emergency lighting. We supply systems that contain up to 6 tonnes of lead in the batteries, but we are not allowed a single gram in the control systems. Sometimes we even supply batteries with cadmium in, and they are banned for all other applications.
However, lead based batteries are about 99% recycled, so much better for the environment than lithium. The scrap metal merchants will pay £500 for a 840Ah lead-acid battery, but it will cost a similar amount for you to dispose of a similarly sized lithium battery.

A final thought - why has no-one banned red LEDs because of their arsenic content?
 

Thread Starter

rambomhtri

Joined Nov 9, 2015
574
Okay, so now my question is... will my repairs be of less quality or reliability because of the use of lead-free instead of leaded solder?

I am thinking for example a very bad scenario like when I have to solder to a battery surface (quite tough to do, but over time I learnt to do it), or when I have to tin and solder very tiny thin enameled cables. Will these works be a nightmare with lead-free solder?

1712839524392.png 1712839588537.png 1712839638868.png

The most difficult job I've made was repairing a hearing aid device. Never in my life I have worked with such thin cables, a complete nightmare. If lead-free solder adds difficulty to that...
 

Ian0

Joined Aug 7, 2020
10,076
It makes very little difference, provided you don’t use the 99S, which is rubbish (and suffers with tin pest)
The only real difference I have noted is that soldering iron tips corrode more quickly.
Good old Weller TCP tips don’t last at all. The new Weller irons are better.
As for repairs, the best solder for a repair is the same solder that is already on the joint.
 

Janis59

Joined Aug 21, 2017
1,856
The lead is known so much <deadly bad>, that I beginning to solder in age of five and still soldering at my 65 every day 8 hours or longer have still a larger probability to die from lead bullet shoot from inter-gang shooting on the street nor due the breathing the lead fumes. And none is much jumping-up knowing that cadmium toxicity is far above the lead, the same about the most of the rare metals - bismuth, cadmium, zinc, copper, berillium etc etc.
 

nsaspook

Joined Aug 27, 2009
13,443
OK, so 60/40 Tin/Lead is “Beginners’ solder”! But I know exactly what you mean. It is rather forgiving!
I shouldn't need to for electronic techs but I've held work classes on soldering after looking at some the 'failed' equipment repairs due to simple soldering. The blob/cold solder method seems to be what's learned on the street these days. :eek:
1712846526168.png
 

Ian0

Joined Aug 7, 2020
10,076
I shouldn't need to for electronic techs but I've held work classes on soldering after looking at some the 'failed' equipment repairs due to simple soldering. The blob/cold solder method seems to be what's learned on the street these days. :eek:
View attachment 319742
Numbers 3 and 4 can happen if you are not paying attention and the pad connects to a much larger area of copper than the others.
 

WBahn

Joined Mar 31, 2012
30,252
Okay, so now my question is... will my repairs be of less quality or reliability because of the use of lead-free instead of leaded solder?

I am thinking for example a very bad scenario like when I have to solder to a battery surface (quite tough to do, but over time I learnt to do it), or when I have to tin and solder very tiny thin enameled cables. Will these works be a nightmare with lead-free solder?

The most difficult job I've made was repairing a hearing aid device. Never in my life I have worked with such thin cables, a complete nightmare. If lead-free solder adds difficulty to that...
It's a matter of skill and practice. Sn/Pb is probably one of the easiest solders to get proficient with, but most of the others become about as easy if you put in the time and practice. I wouldn't be surprised if someone that has never soldered using Sn/Pb and suddenly had to didn't think it was tricky at first, not because it's more difficult, but just because it's different than what they are used to.

The trickiest soldering I ever had to do was to solder voltage taps onto the side of superconducting wire samples that was going to be mechanically compressed. The wire was basically AWG #24 and the voltage taps were AWG #46 and no solder could be allowed to get on the top or the bottom of the wire while the distance between the taps need to be right at 1/4". When I was first told I needed to do that, I thought they were crazy. But after an afternoon of practicing and some trial and error with technique, I got so that I could mount taps on a sample quickly and successfully with no failures.
 
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