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Leaded Solder — Parallax Forums

Leaded Solder

Yeah, I still use it, so sue me. Nothing flows like leaded solder. My 0.025" spool of is running low, so I went looking on Ebay. TTYTT, I expected to see a lot from China, and was fully prepared to make some wisecracks about how solder is the only thing you WANT lead in from China...

But I see none from China. All I see exclusively is the same US manufacturer as my original spool, MG Chemicals: https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_blrs=spell_check&_nkw=leaded+solder+1/2lb&_sop=15

So what happens when MG goes out of business? Will lead futures skyrocket? Is lead the new lithium? Should I stockpile now? Make my garage a toxic material storage facility?



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Comments

  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2018-02-15 03:04
    Sure as eggs, the stuff from China will have lead anyway :) Everyone has to use and order "lead free" but they really want the good stuff.

    There's plenty of lead solder stuff from AIM for instance. I use SN63 PB37 0.015 and 0.032 Glowcore and Mouser seems to stock it.

    ( I checked because you had me scared. Wot! no lead solder! )

    DANG: I forgot, you are Erco the Scrooge, you only buy cheap stuff from China! :)
  • Leaded solder should be available for awhile for hobbyists. The lead is really only an issue for stuff that is dumped in landfills in mass quantities. So for consumer devices made in the millions, yeah, ROHS is kind of important, but the few things we make on our workbenches aren't significant in the big scheme of things, and for our handheld techniques leaded solder does work a lot better. I recently got several big rolls from Electronics Goldmine which should tide me over for awhile.
  • I don't think there will ever be a problem with lead solder availability. It's just too easy to work with, and the other stuff is not. 63/37 is the only solder I use, in wire or paste form -- even for prototypes to customers. Let the major assembly houses deal with RoHS. I can't be bothered for the low-volume assemblies I deal with.

    -Phil
  • Erco, this eBay find would actually be everything we think it is. Those same rolls of solder in China (of course you have to get yourself over there) are $7 in the SEG component market in Shenzhen. I used to regularly bring them back.

    Now, they're also offering FREE SHIPPING but the price is around $16/roll. But it's not really free, as you know. This time they're pushing the limits of our government-subsidized ePacket Category 3 rate for China (and Bangladesh) and building their cost (a couple of dollars since it's over 5 oz) into the price of the product. They know we are addicted to something called free shipping, even though it's not free. We pay for it, in taxes, in the cost of the solder, in our conscience. . . .

    :)

    Ken Gracey
  • Erco,

    Kester was still available the last time I checked.
    Is 0.025" good for SMT?
  • ercoerco Posts: 20,244
    Genetix wrote: »
    Is 0.025" good for SMT?

    For what little SMT work I've done, it worked fine. But TYTT, I use the blob methods this guy shows, and I think larger diameters would work just as well. Dude make it look easy!



  • WBA ConsultingWBA Consulting Posts: 2,933
    edited 2018-02-15 08:30
    Erco, there are several options available for good old 63/37 leaded solder. At work, we stock Kester 275 flux cored solder wire for no-clean in both tin/lead and lead free flavors. For water soluble, we use Kester 331 flux cored solder wire, also both tin-lead and lead free. We use diameters from 0.012" to 0.040" daily. Of the 191,427 boards we ran off our SMT lines last year, just over 51% were tin/lead. So, of course I ignore concerns about availability of tin/lead solder. It will be around for many years to come, despite all of the "opinions of the internet".

    If you are bored at the end of this month, come to the IPC APEX show in San Diego. I can almost guarantee that you can get some samples of tin/lead solder from several solder vendors, ;-)
    I will be there on the 27th looking at several machines.

    In my opinion, the blob/drag soldering method for fine pitch leaded parts is great for hobby use, but my rework techs can solder twice as fast using the standard method of one pin at a time. This is accomplished because no touch up is ever required, clean up is minimal, and consistency is much higher. In 27 years in electronics manufacturing at 4 different companies, I have never seen a skilled rework person use the drag method for fine pitch. (including myself when I was a rework tech at HP many moons ago) The only place I have used drag soldering was with PLCCs, which is uncommon nowadays. To be fair, that video is from John Gammell, a certified master IPC trainer, so of course his work looks really nice and fast, but the technique is not as easy to master as standard soldering.
  • Heater.Heater. Posts: 21,230
    As far as I understand, good old leaded solder is not going away anytime soon. There are all kind of exceptions in the regulation for those who make things that "have" to work. Satellites, avionics, military gear, anti-lock brakes, my hobby projects, etc, etc.

    Me, I just go down to the local electronics corner shop and pick up a spool.

  • You guys can't solder with lead-free?

    The other week I taught someone, who had never held a soldering iron before, to solder in around 30 minutes. Within the hour she was making perfectly reliable and clean LEAD-FREE joints on connectors and PCBs. Maybe it's because she wanted to learn?
  • Heater.Heater. Posts: 21,230
    edited 2018-02-15 11:17
    Maybe it's because she didn't have any choice :)

    We can handle lead-free solder of course. And silver solder and brazing and welding (my welding is pretty bad though, not enough practice)

    No, what it is, it is fear of the whiskers:

    v10_01a.jpg

    http://www.sigcon.com/Pubs/news/10_01.htm

    Besides, do we want to? I want my hobby experience to be fun. Unleaded solder is not fun.

    And also, lead free does nothing to clean up the environment. There is the suggestion that it has the opposite effect:
    https://nepp.nasa.gov/whisker/reference/tech_papers/2011-kostic-pb-free.pdf

    Just say no to lead free.

  • TorTor Posts: 2,010
    Within the hour she was making perfectly reliable and clean LEAD-FREE joints on connectors and PCBs.
    You won't know if a lead-free joint is reliable until much later. And that's a big difference from traditional soldering.

  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2018-02-15 16:57
    As noted by others, leaded solder ain't going no where for hobbyists as long as places like Jameco still sell it by the pound spool.

    Lead-free solder requires up to 50-100 degrees F hotter temperatures. Solder has to be hot enough as it is; even hotter is not ideal for beginners.
  • Heater.Heater. Posts: 21,230
    Good point.

    Doesn't all that extra heat corrode soldering iron tips more quickly?

    Not to mention the increased risk of damaging chips and such with a hotter iron.
  • There's also the issue of poisoning. Not lead poisoning but the fumes from the flux. Due to the higher temperatures and more aggressive fluxes used for lead-free solder, companies where hand soldering is done have been advised that it's important to upgrade fume extraction equipment so as to protect workers' health. How many of us use fume extractors when soldering at home? I know I don't: I have on occasion used an old computer fan that sucks fumes away through a carbon filter I wrapped around it - but most of the time I can't be bothered to set that up - all I do is occasionally use my breath to blow the smoke away when I see it drifting towards my eyes.
  • I may touch a few nerves with this statement, but anyone who has had trouble with lead-free soldering is more than likely not using the proper equipment. The ONLY difference between soldering with lead-free and tin-lead solder is the required specs for the equipment. The technique/methods to solder either is exactly the same for reflow, wave, and hand soldering processes. For example, at work we use the same equipment for both with just these changes:

    The only SMT Reflow difference: thermal profile settings on the oven.
    The only Wavesolder difference: preheat and pot temperature settings.
    The only Handsoldering difference: higher tip temperature cartridge.
    We use the same liquid fluxes for Wave/handsoldering for either tin-lead or lead-free.

    As someone that has controlled/specified/trained for all 3 of these soldering processes in production environments since lead free came in to existence, I am still amazed at all the negativity about soldering lead free. The cosmetic appearance is different, but that is not indicative of the actual soldering process.
  • If you're building something that has to meet RoHS standards, then -- yes, of course -- you have to use lead-free solder. Outside of that, there's no good reason to.

    -Phil
  • That NASA article linked to by Heater has amazing micro-photos of tin whiskers, also, case studies of where they have wreaked havoc. It's alchemy that the conditions that give rise to whiskers are still so poorly understood, or why again, even 3% lead content in the solder will forestall whisker growth.

    I do have to meet Rohs for some things, but not for prototypes. I've had questions about mixing technologies. Lead-free components or lead-free HASL PCBs with eutectic Pb/Sn solder. It seems the consensus it that is okay until the product is too stressed, say by temperature, vibration, etc.

  • evanhevanh Posts: 15,126
    Personally, I bought a roll of lead-free at work for doing my quick repair work - plugs on cables mostly. I figured it's worth a shot. It wasn't as easy to use at all, the flux wasn't cleaning the wire/pin anywhere near as well as the leaded version and the faster thermal conduction was a fright too. Without even raising the iron temperature it melted the insulation way too quick and the joint just didn't feel sound.

    So I put that solder aside and went back to leaded. And that's without considering potential for whiskering or difference in fume toxicity.

    I'm wondering if maybe there is old rubbish unleaded product in the supply system that ends up on workshop benches and give it the bad name.

  • I do have to meet Rohs for some things, but not for prototypes.
    Same here. I pay an assembly house to do the lead-free work, however.

    -Phil
  • ercoerco Posts: 20,244
    Interesting comments, facts & opinions here. I think we all wish lead-free was an easy swap. Seems like many old timers prefer lead (hasn't killed us yet...). When I demoed robots at Maker Faire, there were LOTS of kids interested in those $4 line follower robots, which unfortunately do require soldering. That's a deal breaker for most kids.

    What to do? I wouldn't suggest for a kid use lead.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2018-02-15 23:27
    erco wrote:
    What to do? I wouldn't suggest for a kid use lead.
    Really? I think the danger is way overstated. Kids can be taught to handle lead safely. I mean, how many kids are introduced to fishing using lead sinkers crimped onto the line between the bobber and their wormy hooks? Or, in this part of the world, using lead jigs to catch salmon or halibut?

    When I was a Cub Scout, we had our annual picnic at the F.O.P. cabin outside of town. They had a shooting range, and we would take our pocketknives and dig lead slugs out of the timbers that held the targets up. After we got home, we'd melt the lead and pour it into molds. That's how I learned (almost the hard way, could've been worse) that you never pour lead into a wet mold!

    Obviously, you don't want toddlers eating lead paint from peeling windowsills. And you certainly don't want to breathe in lead dust. But soldering with an iron and spooled lead solder is so benign as to be almost not worth mentioning.

    -Phil
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2018-02-16 00:21
    For kids the danger lies in ingesting the solder, so obviously keep out of reach of young children, and teach older children that solder is not a toy. Lead-free solders still contain heavy metals such as bismuth. Granted, bismuth is not as poisonous as lead, but caution must still be exercised in handling it. The major "danger" to casual users of solder is lead absorption through skin, which is why washing hands with soap and warm water afterword is recommended no matter what you use.

    The "deal breaker" against soldering for kids is not that there's lead in the solder, but that soldering irons operate at >750 degrees F. Even a brief contact with the iron can cause third degree burns, which can produce least temporary scarring at least. On someone with sensitive skin, the burns can lead to deeper necrosis and even infection.

    For kids electronics, what we really need are solder-free solutions, not lead-free ones. For a kids robot book I wrote last year, there were no projects involving any kind of soldering. I can tell you it was a challenge!


  • Heater.Heater. Posts: 21,230
    What age kids are we talking about?

    Certainly very young ones will not be up to handling solder or hot irons with care. Having been to few Maker events and seen a lot of kids of all ages milling around I would say soldering there is a no-no. Unless one can organize some very careful supervision.

    Back in the day, aged 9, I had a Philips Electronics Engineer kit. Lots of projects to make. All done with components pushed into spring clips. Easy and safe. Also means those components were reusable which was essential as they were so rare for us at the time.

    By the time we were 13 we were silver soldering and brazing in the metal shop at school. Electronic soldering was a given for many of us.

    The lower temps required for leaded solder seems like the safer bet here.

  • Raise your hand if you have burned yourself more than once with a soldering iron...
    It's not 'if' you will learn that an iron is hot, but 'when', and how often...sigh.
  • Both hands raised. (Gotta learn which end to grab!) No permanent damage.

    -Phil
  • Ttailspin wrote: »
    Raise your hand if you have burned yourself more than once with a soldering iron...
    It's not 'if' you will learn that an iron is hot, but 'when', and how often...sigh.
    Just once . . . this year that is :smile:
  • And a cold iron looks exactly like a hot one...

    Enjoy

    Mike
  • We live in a different world (just look at current events for any week!) so our youth experiences are completely meaningless. Besides, who as kids didn't roll their eyes when ours parents tried to boast, "When I was your age, I..." And here y'all are doing the same annoying thing!

    Parents are the ones that buy these kits, and today's parents are more cautious. That simple. The trend has been building for decades. Witness such popular products like the Snap electronics kits, or Radio Shack's completely solderless X-In-1 electronics kits.

    Most parents aren't going to ask about the lead in solder, because they simply don't know. They are far more concerned about their kids cutting or burning themselves. That concern turns into not buying things, so it stands to reason if you want to break down the purchasing barrier, create educational products that don't require soldering. Sure, it'll cost more, but parents WILL spend the extra.

    Ever wondered why Parallax's robot kits don't need soldering to complete the basic learning modules? This is not by accident.
  • evanhevanh Posts: 15,126
    "Parents", in this case, just means the cotton-wool mums. Getting burnt is just another of life's experiences for everyone else.

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