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Lead-Free Solder - friend or foe?
May 8, 2014 12:25 PM   Subscribe

Lead-Free Solder - friend or foe? In 2005, the U.S. Environmental Protection Agency published a report (pdf), in which it assessed the environmental impact of tin-lead vs lead-free solder. In July 2006, RoHS legislation banned the use of lead in electronic products destined for sale throughout Europe with a few exceptions.
But not everyone thinks this was a good idea:
While lead may pose a greater public health problem than SAC solder (Tin–silver–copper), the latter uses noticeably more energy to produce than lead–tin solder. Tin Whiskers have also been identified as the cause of many military, health, industrial and satellite failures.
posted by Lanark (45 comments total) 20 users marked this as a favorite

 
There's also this pdf presentation from NASA that wildly criticizes RoHS's lead prohibitions. Slides 10 through 20 are particularly damning.
posted by atbash at 12:39 PM on May 8 [6 favorites]


OTOH, lead-free solder is stronger, which is great if you're subjecting your electrical soldering to mechanical stresses (which you probably shouldn't do, but which I can do in my own projects because it's my party and I'll cry if I want to :) )
And it's soooo much cheaper and easier to obtain lead-free solder now that it's a standard rather than a specialty item.

Lead-free solder also stays shinier and prettier. :-p
posted by anonymisc at 12:41 PM on May 8


When my Dad soldered he would always unwind about a foot of lead solder, and put the end in his mouth bend it at a 90 degree angle.

He's been doing it for 40 years and doesn't have mouth cancer yet!
posted by MisantropicPainforest at 12:43 PM on May 8


lead-free solder is stronger, which is great if you're subjecting your electrical soldering to mechanical stresses

Of course, mechanical stresses are the proximate cause of the tin whiskers, which will then cause the joints to be weaker.
posted by atbash at 12:43 PM on May 8


It may be prettier, but it just doesn't flow like the leaded stuff does. Soldering is much more productive and fun with leaded versus lead-free.
posted by spiderskull at 12:44 PM on May 8


it's funny you mention this... awhile back, we had to re-flow our PS3, because the lead-free solder was brittle and caused a yellow light of death.

This is not an uncommon problem.
posted by markkraft at 12:48 PM on May 8 [1 favorite]


As a terrible solderer I appreciate lead solder's lower melting point. It is a tough call - lead is a fantastic chemical with a lot of amazing industrial uses. Too bad it's one of the worst things from a public health perspective.
posted by GuyZero at 12:57 PM on May 8


lead-free solder is stronger, which is great if you're subjecting your electrical soldering to mechanical stresses.

See the NASA slides I linked to above - they debunk the idea that this use of solder has any public health effects at all.
posted by atbash at 12:58 PM on May 8


Lead-free eutectic solder* is crazy expensive, probably equal parts audiophile markup and the insane precious metals market (silver). Although I use it anyway for cabling headphones and earphones because I refuse to wear something with lead joints near my skin, even if they're sealed in glue and heat-shrink. Fortunately, so far one relatively small coil has been lasting me for years.
* (Solder that transitions from liquid to solid without a soft paste phase. The classic go-to eutectic solder is tin/lead 63/37.)
posted by ardgedee at 12:59 PM on May 8 [1 favorite]


The lead-free solder is kind of a pain to unsolder, but I feel guilty whenever I use lead solder.
posted by drezdn at 1:04 PM on May 8


As a matter of priority I'm pretty sure coal-fired power plants should come long before the electronics industry. The Union of Concerned Scientists describes 114 lb lead pollutants per year per plant as "typical". Does the production of bioavailable lead pollutants from all the soldering in the world really even compare to that?
posted by George_Spiggott at 1:06 PM on May 8 [13 favorites]


Based on the NASA slides atbash linked, the annual worldwide lead reduction from converting 1,000,000,000 ICs to lead-free is about the same as that contained in 100 car batteries, or a teeny tiny fraction of all the car batteries not properly recycled every year.
posted by zachlipton at 1:19 PM on May 8 [5 favorites]


This is definitely the case of fixing what you can fix based on who is willing to make fixes rather than fixing what actually needs to get fixed.

People who burn coal and make auto batteries don't want to make any changes, electronics manufacturers do.

I guess it's better than nothing.
posted by GuyZero at 1:21 PM on May 8 [9 favorites]


the annual worldwide lead reduction from converting 1,000,000,000 ICs to lead-free is about the same as that contained in 100 car batteries, or a teeny tiny fraction of all the car batteries not properly recycled every year.

... and also neither solder nor car batteries result in bioavailable lead as far as they can see.
posted by atbash at 1:32 PM on May 8 [1 favorite]


See the NASA slides I linked to above - they debunk the idea that this use of solder has any public health effects at all.

That's a non-sequitur. I was talking about silver solder offering a harder alloy than lead solder, I wasn't talking about public health effects.
posted by anonymisc at 1:34 PM on May 8


While lead may pose a greater public health problem than SAC solder (Tin–silver–copper), the latter uses noticeably more energy to produce than lead–tin solder.

It is often case that environmentally friendly processes cost more in money or resources than the existing methods, mainly because the existing methods are frequently the cheapest ones possible.

If you want to evaluate methods you need to compare the damage caused by the additional energy production vs. the damage caused by the existing process.
posted by Tell Me No Lies at 1:42 PM on May 8 [1 favorite]


That's a non-sequitur. I was talking about silver solder offering a harder alloy than lead solder, I wasn't talking about public health effects.

Which itself was a non-sequitur given the point of the thread no?
posted by srboisvert at 1:42 PM on May 8


awhile back, we had to re-flow our PS3, because the lead-free solder was brittle and caused a yellow light of death.

That's not... precisely the message I got from the video...
posted by Naberius at 1:43 PM on May 8 [1 favorite]


Which itself was a non-sequitur given the point of the thread no?

No. The thread and material in the links are about a lot more than health effects, and they include weighings of pros and cons. I mentioned some of the advantages that I like about some of the lead-free solders.
posted by anonymisc at 1:47 PM on May 8


(Disadvantages in one scenario can be advantages in a different scenario, and vice versa)
posted by anonymisc at 1:50 PM on May 8


atbash: "See the NASA slides I linked to above - they debunk the idea that this use of solder has any public health effects at all."

No they don't, they just say there is "no evidence", when in fact there is. Here's one: Elevated Blood Lead Levels of Children in Guiyu, an Electronic Waste Recycling Town in China. Should I just post the google results? It could take awhile.

But wait there's more!
•"Lead does not break down in the environment. Once lead falls on
to soil, it usually sticks to the soil particles.”- Ohio Department of Health 08/10/09, “Lead Answers to Frequently Asked Health Questions”

Note the "usually". Or you have an environment where you can mobilize it and it can leach out of the soil, like a landfill.... Which they even admit earlier: However, as the alkalinity and pH decreases the mobility of lead increases.
posted by Big_B at 1:54 PM on May 8 [2 favorites]


That's a non-sequitur. I was talking about silver solder offering a harder alloy than lead solder, I wasn't talking about public health effects.

You're absolutely right, and it's because I meant to copy-paste GuyZero's statement above mine instead.
posted by atbash at 1:54 PM on May 8


The additional tin mining required to produce high-purity tin alloys, plus the mining of other precious metals required to alloy with tin in substitution for lead is a poor trade for the use of existing lead, much of which comes from recycled products.

Less lead smelting and less lead in discarded electronics means less lead in food, water and air. Since there is no safe level of exposure to lead, this seems like a net positive, even if alternatives cost more money (which is the real objection, at the most basic level).
posted by Blazecock Pileon at 1:55 PM on May 8 [1 favorite]


Since there is no safe level of exposure to lead, this seems like a net positive, even if alternatives cost more money (which is the real objection, at the most basic level).

Well, sure, less lead in the world is a good thing in the abstract, but the real objection isn't just cost, it's that there are critical technical problems with the lead-free technology, problems that we know very little about, but which can cause catastrophic failure of critical systems. It's merely costly and annoying when this causes your PS3 to fail, but downright dangerous when it causes failures in critical aircraft, spacecraft, automotive, or medical device parts.
posted by zachlipton at 2:08 PM on May 8 [1 favorite]


It might be a good idea for critical systems to have double- or triple-redundancy, as multiple simultaneous systems failures are rare. Military craft apply this approach, I believe. But redundancy costs money, so again, it just seems like a cost issue at its core.
posted by Blazecock Pileon at 2:27 PM on May 8 [1 favorite]


Yes but there's a difference in number between 50 billion CPUs in PCS vs the tens of thousands used in avionics.

Your PC CPU is most likely going to be incinerated to recover the gold, silver and copper. The fact that the lead gets carried away with the smoke is a bonus not a problem to the less scrupulous recyclers. That's why we had to take lead out of components.
posted by Talez at 2:28 PM on May 8 [1 favorite]


It might be a good idea for critical systems to have double- or triple-redundancy, as multiple simultaneous systems failures are rare. Military craft apply this approach, I believe. But redundancy costs money, so again, it just seems like a cost issue at its core.

The trouble is that poor solder is a systemic bias issue. If all redundant systems suffer from the same failure mode of broken solder joints or tin whiskers then you don't really have any redundancy.
posted by GuyZero at 2:39 PM on May 8 [2 favorites]


Or get rid of the less scrupulous recyclers.
posted by Monday, stony Monday at 3:08 PM on May 8


Lead-free solder is also a pain in the ass to work with if you're used to the leaded stuff.
I've stocked up on my favorite Kester 245 63/37.
posted by mrbill at 3:08 PM on May 8


Extensive redundancy in equipment going into outer space gets real expensive real fast, where launch payloads are budgeted in grams.
posted by ardgedee at 3:35 PM on May 8


I thought you said lead-free soldier and that you were talking abou tthe little toy green army men.
I am so disappointed.
posted by SLC Mom at 3:41 PM on May 8 [1 favorite]


I like my lead-free; it's really easy, and anyone who say's it's at all difficult to work lead free must be hopelessly ham-fisted. Y'all have flux pens, right? You're not trying to solder lead-free without a flux pen, are you? 'Cos that would be horrible.

I turned off to that NASA report when it got all snide about the Precautionary Principle. It's also very much lacking in citations, and the whole bit about "zOMG lead cures tin whiskers" is kind of shot down by the examples from NASA and Bell of whiskers growing in leaded assemblies.
posted by scruss at 3:45 PM on May 8 [2 favorites]


Disposal's not just an environmental risk; PCB's aren't just thrown in landfills anymore. Electronics get recycled now, which often involves being picked apart by humans by hand in a developing country with lax health and safety standards. For their sake, fuck lead.
posted by Sys Rq at 3:45 PM on May 8 [1 favorite]


You're not trying to solder lead-free without a flux pen, are you? 'Cos that would be horrible.

yes, yes I am. because I are a bad solderer. If I need flux I just melt more solder.

Maybe I'll go buy some flux.
posted by GuyZero at 4:33 PM on May 8


Get a pot of paste flux from Radio Shack for five bucks. It'll last you years. I use a toothpick for applying it to small joints, which is the scale of most hobbyist electronics soldering, I imagine.
posted by ardgedee at 4:54 PM on May 8


Or get rid of the less scrupulous recyclers.

Yes. That's perfectly practical. If only we could get rid of the less scrupulous humans. Then we could completely eliminate locks on doors!
posted by Talez at 4:58 PM on May 8


Good pipe dope contains lead. But most of the big companies around here (gas utility for example) have switched to the lead free varients because the pipe fitters were showing elevated lead levels in their blood.

MisantropicPainforest: "He's been doing it for 40 years and doesn't have mouth cancer yet!"

Can he count past ten when it isn't sandal weather?
posted by Mitheral at 5:43 PM on May 8


awhile back, we had to re-flow our PS3

We've owned an older PS3 (the large type) since 2009 and oddly enough it hasn't failed. I suspect it's because it's been powered on 99% of the time, so perhaps the solder connections go through less cycling from a cold to warm state. My cousin did have to re-flow his.
posted by crapmatic at 6:10 PM on May 8


The lead-free solder is kind of a pain to unsolder, but I feel guilty whenever I use lead solder.

Wait, is this why I always see the advice "you can always just unsolder it and do it again" but my pile of various wicks and bulbs and ruined components is almost as big as my pile of completed projects? Not that I'm going to start using lead solder in my tiny, poorly ventilated apartment but I'd certainly start cutting my losses sooner.
posted by Room 641-A at 6:57 PM on May 8


but my pile of various wicks and bulbs […]
You are using a wick designed for lead-free solder, right? Check the label, it makes a big difference.
posted by b1tr0t at 8:06 PM on May 8


Strap on your skeptic hat. One crusty old engineer has a thing for lead solder, writes a long screed about on his blog - citing the "myths" of going lead free. An ECN editor picks up the story, doesn't add much other than to add a quote from a body in the IC packaging industry saying nobody's has checked since to see if it made a difference and in any case it was only a problem for the third world. It makes a great story - look at those idiots regulating industry to protect the environment - they're so stupid they actually made it worse. Maybe there's another agenda at work in that point of view.

The electronics industry spent billions on this change - I was part of it - it was a pain in the ass. But we did it anyway to keep lead out of landfills. Frankly, we (in the affected companies) didn't know if it was really dangerous or not - but the industry followed the new regulations out of Europe and Japan without a huge knockdown fight and we didn't spend a fortune trying to discredit the scientists and regulators that said lead was bad. That seems like the right thing to do - a responsible way for industry to act - we don't need to run a global experiment to see if lead buried in landfills is good or bad even if it's "only" in the third world.

Obligatory cartoon.
posted by Long Way To Go at 8:36 PM on May 8 [13 favorites]


You are using a wick designed for lead-free solder, right? Check the label, it makes a big difference.

I doesn't say, but it's from Radio Shack so probably? I'll try to find it on the website, thanks. I have a bad habit of snapping chips in upside down and those might just be harder to undo.
posted by Room 641-A at 9:01 PM on May 8


That seems like the right thing to do - a responsible way for industry to act - we don't need to run a global experiment to see if lead buried in landfills is good or bad even if it's "only" in the third world.

Thanks for doing your part.
posted by Blazecock Pileon at 10:54 PM on May 8 [1 favorite]


I came for the lead free soldiers. Wargame doh!
posted by Capricorn13 at 6:26 PM on May 9 [2 favorites]


Room 641-A, I'd assume that if it came from Radio Shack it would be minimally up to the lightest duty use of the average user. In other words, not usable with lead-free.
posted by scruss at 7:40 PM on May 9


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