The Case for Lead-based Solder

[sburrow]

Hey again everyone!

Another general question, and want your opinions and thoughts, perhaps a link or two.

I personally think that lead-based solders are great. I haven't used any other type, but I have had zero issue using what I've used so far, and do not plan on using something else. I have likewise heard stories of non-lead-based solders coming undone or something going wrong.

I'm guessing there are different percentages, different trace elements, different applications, etc. But overall, the solder either has lead, or it doesn't. The main reason I see for folks to use non-lead-based solder is for environmental/health reasons. Ok cool, whatever floats your boat. But when it comes to the physics, is there any advantage that non-lead-based solders have? Would there be any use for a "weekend warrior" hobbyist to be using a non-lead-based solder?

At the same time, I've heard how "it has been found that lead based solders can cause cancer in the State of California" (I guess Texans are immune to lead solder cancers). Is this REALLY true? When I'm soldering and only crack my window a smidge, am I killing brain cells?

Do any of you have links or data on the safety or lack thereof of lead-based solders? Any studies online I can read? Anything *reliable*?

Any personal experiences with this? Or thoughts? Just a general discussion.

Thanks everyone!

Chad

[BigEd]

AIUI, lead in the environment is bad, because it's a cumulative poison, with an affinity for the brain, and it particularly affects the very young, who are still growing their brains.

Much like the situation with smoking and health, there will be many people who are not affected, who might think that it's a fuss over nothing, but there will also be many who are affected. Older people have less to worry about because they have fewer years ahead of them.

So, leaded solder, as solder, may be easier to work with, but it has disadvantages for people (and animals) and especially children.

Oh, and pregnant women, of course, have particular concerns.

Personally, I'd trust government sites:
site:gov.uk lead toxicity
site:gov lead toxicity
site:europa.eu lead toxicity
and I'd trust the World Health Organisation
site:who.int lead toxicity

Looks like there are cardiovascular risks as well as neurological risks.

[floobydust]

Well, let's face it... lead is not good for you. period. But then again, you're not suppose to ingest it either. I grew up in the 60's and 70's... lead-based paint, leaded gasoline, leaded solder in all household plumbing and lots more. I started soldering 60 years ago.... have handled countless pounds of solder over the decades (and no gloves). I still use lead-based solder... they still make lead-based solder. In California, pretty much everything gives you cancer. Almost every product has a cancer warning specific to California, but almost no other state (US that is).

Bottom line, you should do your own research and feel comfortable with the decisions you're making when buying materials, parts and such. Unless you're planning on soldering daily for hours on end (which I did for 4+ years), I don't think it's going to matter much as a home hobbyist. However, if you are planning to do a large amount of soldering, get some exhaust equipment as the fumes from the rosin flux will be more of an immediate health issue

[BigDumbDinosaur]

My take on it is the world is full of Chicken Little types who find something bad in every technological advance. In that respect, the wackos who are running (or is it ruining?) California are over the top. As flooby notes, it seems everything in that state has been declared to be a carcinogen. I hear burritos can cause colon cancer. (Disclaimer: I like burritos, so I guess my days are numbered.)

As for leaded solder, it has a lower melting point than non-leaded, which means you pour less heat into the part and the PCB, reducing the danger of damage. Use of non-leaded solder in electrical work increases the probability of a cold joint that may not manifest itself for many years until the assembly is subjected to a sudden thermal shift. Even commercially-produced assemblies that have been waved or reflowed run into cold joint issues. For these reasons, I will not use non-leaded electrical solder. The leaded stuff continues to be readily available, despite the efforts of the environmentalists who want to ban anything they think is bad. At any given time, I have three to five pounds in various sizes around here, including one roll of 20/80 for railroad applications.

floobydust wrote:

Well, let's face it... lead is not good for you. period. But then again, you're not suppose to ingest it either.

...which is true for countless products. However, let us not underestimate human stupidity.

Being someone who builds large-scale model railroad equipment, as well as does general steel fabrication, I'm constantly working with a bevy of noxious substances and other industrial-style products. Plus I have metal-working machines in my shop that can rapidly remove fingers, eyes, etc. I've been well-aware of the hazards involved since my high school days and despite all the alleged dangers with lead, acetone, trichloroethylene, welding fumes, operating machines, etc., I’m still breathing and still have all my appendages. Oh yes, I almost forgot! I’m an old curmudgeon who is closing in on 80. Now, about all those hazardous substances that should have maimed or killed me long ago...

BigEd wrote:

So, leaded solder, as solder, may be easier to work with, but it has disadvantages for people (and animals) and especially children.

That is true for almost all products that result from chemistry. Think about the processes involved in manufacturing plastics. Many of the dangers are theoretical, not actual, if reasonable precautions are taken. The carelessness of a few thoughtless people should not be the catalyst for the outright banning any product. If that sort of response were commonplace with everything that is a danger, we would have banned automobiles and motorcycles long ago.

Quote:

Personally, I'd trust government sites:

Recent experience in the USA regarding COVID-19 has made me distrustful of government sites. These are politicians and bureaucrats who are making the proclamations and demanding we march in lockstep with their policies. The scientists and medical experts who actually research this stuff are not dictatorial and mostly understand the balance between safety and practicality.

Quote:

and I'd trust the World Health Organisation

...an organization staffed by more politicians and bureaucrats who are trying to force one-size-fits-all policies on the world.

Getting back to the original question, I see absolutely no reason to not use leaded solder. As flooby says, the fumes produced by the flux are more a concern than the lead in the solder. Don’t eat the solder and use a blower to dissipate the fumes, and you’ll be fine.

[BigEd]

Colour me unsurprised.

[GARTHWILSON]

The big concern is that lead in the landfills will get into the groundwater. Once a year, our water bill comes with a water quality report, which I started watching particularly for lead content since all of this stuff about RoHS ("row-hoss," Europe's Restriction of Hazardous Substances) started up. There's a landfill five miles from us, with three-quarters of a century of electronics trash in it. The water quality report has continually said that the lead level is one-eighth of the action level; IOW, if it got eight times as high, they'd have to do something about it. It has not been increasing. However, it also says that the landfill is not one of the suspected sources, but erosion of natural deposits is. Meanwhile, the car-battery industry is using 75% of the lead produced, and the electronics industry never used more than a very small percentage, maybe 2% but I don't remember for sure; and there's no restriction on lead for car batteries.

Without lead, solder tends to crack more easily. Consumer PC accessory boards I've gotten that were RoHS quickly got cracks in the solder connections that had to handle some stress, like an SD-card socket. Re-soldering with leaded solder fixed them, and kept them working. At work, we got a batch of boards from an assembler in the Orient a year or two ago who neglected to read our instructions and assembled the boards with no-lead solder, and some of the taller parts (tiny SMT electrolytic capacitors) got knocked off in the shipping before they even reached us. The solder had broken.

Without lead, solder also tends to grow tiny tin "whiskers" which short to neighboring pins.

These are the reasons why, last I read, military and medical electronics are still not allowed to use no-lead solder. I have not kept up with the latest, but I think there has been progress in the tin-whisker area, by adjusting the content of various metals in the solder. Still, our company has told the European market that they're not worth it. If someone in Europe wants to buy our products, they can, but the quantities won't be high enough for authorities to raise an eyebrow and want some investigation or certification, or if they did, the importer, not us, will have to deal with it. So we still specify and use leaded solder.

Leaded solder always need a higher temperature to melt it, which can be less friendly to components. (I see BDD addressed this above, while I was writing.) However, this has been taken into account in manufacturing the components, and in the temperature profiles used in automated soldering equipment, so I don't think the higher temperatures are actually damaging any components.

When fishing, my dad always used to crimp the lead weights onto the line by biting them, meaning he was undoubtedly getting lead on his teeth and subsequently swallowing it. He's 86, and if there's any decline in mental sharpness, it's undoubtedly from other dietary habits. I spent years in a boarding school in another country where our water came to us in lead pipes. A high percentage of those kids went on to become doctors and engineers; so I'd say the lead didn't have any negative impact on our brains.

As for breathing fumes, I'd say that's only about the flux. I'm sure the vapor pressure of lead at the soldering temperatures we use is much too low to worry about.

In the US, our CDC and FDA are extremely corrupt, which I can heavily document. The fox has been put in charge of guarding the hen house. My perception from a distance is that the UK's equivalents are not quite as bad. That all is another topic though, not very suitable for this forum.

[sburrow]

Thank you everyone, good info.

BigEd wrote:

Much like the situation with smoking and health, there will be many people who are not affected, who might think that it's a fuss over nothing, but there will also be many who are affected.

I am not a smoker, but you can say I was for some time in my life. I wouldn't say I was *ever* a stellar athlete, not sure if I'm any worse for that time or not, but I certainly won't be going back.

BigEd wrote:

Personally, I'd trust government sites

Thank you for the links. Nothing personal Ed, but those are exactly who I wouldn't trust. BDD and Garth make mention of this further down.

floobydust wrote:

I grew up in the 60's and 70's... lead-based paint, leaded gasoline, leaded solder in all household plumbing

My wife says there was a sharp down-tick in moral standards coinciding with lead based fuel. Could be a coincidence though?

BigDumbDinosaur wrote:

However, let us not underestimate human stupidity.

Indeed. This is actually why I'm asking this at all. Not necessarily for myself. But say I tell a friend, "Hey, lead-based solders are the best!" and then he later claims I'm trying to kill him or something. And what if an organization or company endorses lead-based solders, could a customer sue them? All too serious a thought when McDonald's gets sued for not putting "Caution: Hot Contents!" on each. And. Every. Coffee. Cup. It. Sells. Waaayyy too easy to just sue over your personal stupidity. And then legal fees for littler companies could easily bankrupt them.

BigDumbDinosaur wrote:

Recent experience in the USA regarding COVID-19 has made me distrustful of government sites.

If BDD simply distrusts them, I think they are producing anti-truth. If I go further, even here, I might even get "cancelled"!

BigDumbDinosaur wrote:

the fumes produced by the flux are more a concern than the lead in the solder

And those fumes are in ALL solders right? Lead-based and lead-free?

GARTHWILSON wrote:

Without lead, solder tends to crack more easily.

You had once told me this, and it makes sense with what BDD said about the melting point stuff.

GARTHWILSON wrote:

military and medical electronics are still not allowed to use no-lead solder

THAT is a darn good case for leaded solder! Extremely helpful information, thank you. See, it's not just *us*, it's also *them*.

GARTHWILSON wrote:

I'd say the lead didn't have any negative impact on our brains

So many folks say the decline of the Roman Empire was due to lead pipes. Wrong. It was super inflation and government corruption. Hm! I see that very same thing... today.

GARTHWILSON wrote:

I'm sure the vapor pressure of lead at the soldering temperatures we use is much too low to worry about

Yet again, another very good point. When I'm inhaling those fumes, it's flux fumes, not lead fumes! Ah, good ol' gravity.

This has been extremely educational. Thank you all for this insight. Some of these particular comments were extremely on point and exactly what I was looking for.

If anyone else has more to add, I'm more than happy to listen. Thank you all!

Chad

[BigEd]

I think it's good for all of us, and for the health of the forum, to try our best not to politicise discussions.

We all have political opinions, and none of us are likely to be swayed by hearing other's opinions. Airing our opinions, then, is only going to divide us, as we disclose which of several camps we sit in.

The end point of that is that some people feel unwelcome. As I say, it's bad for the forum, the purpose of which is to share and enjoy our interests in and around the 6502.

[BigDumbDinosaur]

BigEd wrote:

I think it's good for all of us, and for the health of the forum, to try our best not to politicise discussions...

Ahem!

BigEd wrote:

Personally, I'd trust government sites:
site:gov.uk lead toxicity
site:gov lead toxicity
site:europa.eu lead toxicity
and I'd trust the World Health Organisation
site:who.int lead toxicity

[barrym95838]

When left squares off against right, one of the first casualties is the truth. That's all this proud Californian has to say about that, on this forum anyway.

[BillG]

History will not be kind on the incompetence of governmental "authorities" in the past several years:

* Dr. Fauci funded the Wuhan lab through the EcoLab Alliance.
* Prolonged shutdown of the economy destroyed numerous small businesses.
* Prolonged shutdown of in-person learning set back the education and indeed the mental health of countless children.
* Prolonged masking requirements harmed the acquisition of spoken language skills by young children.
* Denial of the validity of natural immunity after recovering from COVID led to draconian mandates of vaccines which do not truly block infection or spread.
* CDC credibility destroyed by ever changing guidelines on masking: they do not work, wear one, wear multiple.
* Prolonged paying people to stay at home was a part of the breakdown of the supply chain and businesses continuing to be unable to find help.

[sburrow]

BillG wrote:

History will not be kind on the incompetence of governmental "authorities" in the past several years

I completely agree. But with that said:

BigEd wrote:

I think it's good for all of us, and for the health of the forum, to try our best not to politicise discussions.

Ed, I most certainly had no intention of bringing up politics here. I do not want anyone to feel uncomfortable. But that goes two ways, because "government" or "authorities" are not neutral. Governmental sources are just as "political" as non-governemental sources. See Ed, "government" makes ME feel uncomfortable.

I see you often say (and as BDD pointed out here), "I personally would..." or something similar, which is exactly right. You personally feel one way, and it just so happens that I (in this particular case) feel a different way. That's ok! I certainly don't want to attack your person, by any means! You have been very helpful to me and so many others throughout the years, and I thank you for that.

I am all about staying on topic, but when I get fired up about something that I *personally* have great feelings for, it's hard to resist. Forgive me. It will most likely slip again sometime in the future, so please forgive me then too.

Going back to the topic:

The case of leaded solder has been made for me. Summary:

1) Both leaded and lead-free solders will have flux fumes.
2) Lead is heavier than air, so lead isn't present in the fumes.
3) The dangers of lead are predominantly from ingestion, not so much contact.
4) Washing hands after soldering is a good practice regardless of lead content.
5) American military and medical entities require leaded solder for reliability.

I can't give you proof/links on each one of these, but that's good enough for me *personally*. Anyone else is free to disagree of course.

Thank you all, I appreciate the help on this topic.

Chad

[AndersNielsen]

This thread has gone a bit off track but the facts point to that we have a few generations of people who could’ve had quite a few more IQ points but don’t. Luckily they also managed to ban leaded gasoline before it had enough effect to prevent them from doing so..
So far everything points to ANY amount of lead in your system is bad.

For that reason I don’t use leaded solder - and also because I just can’t find any reason not to use lead free.. Leaded might be more forgiving but I wouldn’t know - I’ve never had any of the issues people complain about.

And no matter what you use: Slightly cranking a window won’t cut it - flux fumes are bad for you too and a carbon filter fan isn’t that expensive.. your health might be.

[BigDumbDinosaur]

AndersNielsen wrote:

So far everything points to ANY amount of lead in your system is bad.

I don’t know if that is an entirely accurate characterization.

Lead occurs naturally in ground water and all living things have been ingesting water with trace amounts of lead in it for millennia. At the risk of being Captain Obvious, it’s likely evolution has caused organisms to adapt to and tolerate lead content as a matter of survival. It’s also highly likely you are regularly ingesting small amounts of lead each time you drink water, consume coffee and/or tea, eat food cooked in water, etc. While in-your-system lead above a certain level is definitely harmful, few of us are exposed to that much lead from casual sources.

Quote:

And no matter what you use: Slightly cranking a window won’t cut it - flux fumes are bad for you too and a carbon filter fan isn’t that expensive.. your health might be.

I’ve been building electronic gadgets since childhood (I built a very simple radio when I was eight, which involved soldering) and have probably had more flux fumes enter my lungs than most could imagine. They must not be that bad, seeing as how I’m 77 years old and still fully cognitive (although my wife might not be 100 percent on-board with that claim). Jus’ saying.

[plasmo]

Perhaps I could’ve been a smarter person, but I guess I’ll never know. I’ve spent 15 years in my 20’s and 30’s shooting pistol competitively. A lead bullet generates fine aerosolized lead powder as it exits the gun barrel and competitive shooters would fire about 200 rounds a week in enclosed indoor range. Many gun ranges now have ventilation system that move air from behind the shooter forward, but not during my days of shooting. Olympic shooters of my day should be brain dead, yet my shooting partner is a smart Olympic class shooter working in technical field well into his retirement age. Just a data point about lead toxicity, for what it is worth.

Oh, yes, I used lead solder ever since my teenage days building Heathkits. I continue to use lead solder to this day.
Bill