Leaded Solder
erco
Posts: 20,256
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?
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?
Comments
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!
-Phil
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
Kester was still available the last time I checked.
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!
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.
https://www.ebay.com/itm/60-40-0-8mm-1-2lbs-Tin-Lead-Rosin-Core-Solder-Flux-Soldering-Welding-Iron-Wire-R/301954335144
Me, I just go down to the local electronics corner shop and pick up a spool.
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?
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:
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.
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.
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.
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.
-Phil
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.
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.
-Phil
What to do? I wouldn't suggest for a kid use lead.
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
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!
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.
It's not 'if' you will learn that an iron is hot, but 'when', and how often...sigh.
-Phil
Enjoy
Mike
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.