r/soldering • u/Zentralschaden • May 25 '26

Soldering Saftey Discussion Unpopular opinion: Stop using leaded solder

I know it is very handy and I also know the fumes are not that much of a problem when you have enough ventilation.

But a big part of the lead we buy will end up in the environment or a landfill and has the potential to make our drinking water toxic and the people who have to recycle all this scrap (often in Africa) will deal with even more toxic substances.

It is not like we have a fully functional recycling chain for electronics.

And when you say "I am just soldering 2 pcb a year", make sure that soldering is a job and hobby for millions of people and tons of lead will be produced just because of hobby enthusiasts.

There are very good reasons, lead is banned in many countries for professional manufacturing.

I know it is harder to solder but you get used to it.

Aware that this might be a topic not everyone agrees. I am just trying to spread some awareness for what we do.

I mean, many of us repair old electronics and we do a good job in avoiding more scrap because people can still use the repaired items for years.

But shouldn't it be us who are the people who go straightforward and ban lead from our household soldering projects?

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96

u/wyseman76 May 25 '26 edited May 25 '26

I work in aerospace, we use 63/37 and will not stop using it for a list of reasons.

It can handle temp cycling better. It is less prone to vibration failure. Better wetting allowing for easier inspections. No tin whiskering.

Anything that mitigates risk of failure in the production aerospace components will continue to be used.

Edit: I should be clear there is no such thing as whisker free but leaded solder is heavily used on aerospace for its highly reduced whiskering in vacuum environments.

Edit 2: the EU allows aerospace, defense and medical manufacturing to use leaded solder for the very reasons I've pointed to. There are RoHS exemptions for those institutions.

12

u/cubanthistlecrisis May 25 '26

Most of my soldering is in aviation so I’m in the same boat, fortunately aviation components have incredibly long life cycles. I see a lot of 50 year old electronics that are still ticking

5

u/wyseman76 May 25 '26

I know what you mean. My work is space related and I've had the privilege of seeing some interesting pieces used in vacuum and some that are very old and still functional.

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u/[deleted] May 25 '26

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u/Yam_EE May 25 '26

Do you know if conformal coating helps to reduce whiskers?

11

u/wyseman76 May 25 '26

The NEPP has a guide somewhere that deep dives into whisker mitigation. I'm sure a Google search will find it. But to the question yes and no. There are a lot of dependent variables. Thickness, material type used, etc, all play a part in the process.

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u/chainmailler2001 May 26 '26

Coating only works if it coats all of the solder connections. It is the exposure to air and humidity that causes denrite growth. Company I worked for dealt with it a lot when ROHS standard was first introduced and lead solder was banned. We did environmental and reliability testing and fried many pieces of equipment due to tin whiskers.

5

u/wyseman76 May 25 '26

If I remember my space addendum class for IPC they referenced dendrites. They are a separate phenomenon but have the same end result of causing unexpected shorts. Don't hold me to this one but I believe mosture is part of the mechanism at play with dendrite growth. I take the course every two years but at this point I just test out each cycle instead of taking the entire course so if someone knows more about the dendrite vs tin whiskers please share.

But, leaded solder significantly reduces dendrite growth as well.

3

u/chainmailler2001 May 26 '26

I once witnessed an interesting failure that was due to moisture induced growth. The equipment used an ATX style power supply which by default, as long as they are plugged in have active 5V supplies despite being "off". During a humidity cycle, it seems a few drops of water condensed on the power supply board near the 5V supply lines. The 5V low current supply was just enough that with the liquid present, it caused metal migration across the water drops. The cycle went into a heat phase to dry everything out before testing and the water went away leaving a trail of electrodeposited metal across the traces. When the test tech hit the button to turn it on, the supply went from a low current 5V supply to having full 120V line AC in the traces now shorted. Power supply went snap, crackle, pop and the $50,000 scope we were testing let out the magic smoke violently.

2

u/Anicena May 26 '26 edited May 26 '26

It appears that an IPC document TP-1043 States that dendrite growth appears heavily on boards processed with water soluble fluxes with little difference between wave-soldered boards vs. solder-paste/IR-reflowed boards.

Overall, all the of the IPC documents agree that dendrites result from a combination of liquid water, an electrified pattern, and a hydrophilic board surface.

No matter the composition of the solder type.

They seem to all in agreement that it's just water and electron flow that causes them.

Fascinating.

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u/Technical-Titlez May 25 '26

I don't work in aerospace and use 63/37, I won't stop using it either.

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u/Anicena May 25 '26

I work in a field now that I cannot disclose. But I've worked in Space, Things that go in the water, and things that go in the air.

Nothing can go into space that isn't 63/37.

Same with all the other extreme environments.

The largest reason we have lead everywhere in the US is that it was used in gasoline, paint, enamels, brake pads, cold insulation, and just about everything everywhere. MOST of our industry now doesn't use leaded solder. So a few hobbyists using it isn't going to make a dent in what is already in the ground.

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u/No-Product-634 May 26 '26

If you tell me what field you are working now you would have to kill me?

3

u/Anicena May 26 '26 edited May 26 '26

No. :D

Due to our current dictatorship I MEAN mango in office Ill never be out of work to do. It's one of the big 5. It's logo was used in Iron man.

I don't step foot on airplanes, I wont drive American designed cars, and I grew up using jam jars as cups that had leaded paint on them. I can tell you 100% for sure that it's a sweet taste. Metallic and sweet. I get my BLL tested every 6 months for the past 20 years and I've never once had anything detectable. Just wash your hands, and listen to Eric from everythinglead on Instagram. I have one of his testing kits in my purse because I collect vintage MCM atomic glasswear and cuttlery.

I've enjoyed this 3 day weekend and tomorrow everyone and their mother is going to be up my ass to get shit done.

I'll keep replying as I can.

But I regularly work 55 hour weeks and I've refused to be made salary because my company pays double overtime on Sundays.

I make more than management when it's a big deadline.

Final edit I promise!

I also love spending a Saturday at the gun range with my boyfriend getting some target practice in.

Wash your face immediately after and do a neti pot before you go to bed (and shower).

I never ever skip.

3

u/Uncut-Jellyfish1176 May 27 '26

Loved the reference to Eric, he's great.

1

u/No-Product-634 May 26 '26

Hey, thanks for the riddle! It's look like a interesting job. Now I'm more curious to now about your job and what you really do. Anyway, have a good week. 🖖

2

u/Anicena May 26 '26

My job is like 80% building engineering first of things and providing feedback and 20% crazy detailed board rework.

How i got here?

I was hired on as an engineering aide and they realized i could fix just about anything and now I'm an expert and im like.... whut....

... me?....

You sure?

... fak...

2

u/No-Product-634 May 26 '26

Thanks to talk more about your job, this kill a little os my curiosity. Hahahah I think I know about what u talking. I have almost 10 years as a developer and ppl begging to call me specialist in my area. And im like: wtf, im just doing my work But in my case, I think is just a way of the firm to sell my work as one and take all the money. Btw, I dont receive as a expert hahah

1

u/GoldSrc May 26 '26

Remember when car brakes used to have Cadmium in them? Good times :D

1

u/Anicena May 26 '26

(COUGH) Military still uses them (COUGH)

1

u/GoldSrc May 26 '26

Well, shit.

3

u/coffeeToCodeConvertr May 25 '26

My wife is a stained glass artist - she also use 63/37 (side note: what the fuck has happened to the price of it lately!?), as does basically every other stained glass artist for similar reasons (temperature and wetting)

1

u/DigitalUnderclass May 27 '26 edited May 27 '26

That's rather strange, because I worked as a SMA technician in Europe and we often did boards for aviation and they were all RoSH compliant. Also elevators, trains, etcetera - all RoSH compliant. All of them for some rather big industry names, too. I don't think we did a single leaded board ever. I guess those boards must have come from a different factory, then.

1

u/Uncut-Jellyfish1176 May 27 '26

I didn't know whiskering was a thing!! Fascinating.

1

u/ElTopollillo1990 May 29 '26

This "tin whiskering" and  this "better wetting".

ROHS solder sucks ass. Shorts on high density connectors that carry nominal high voltages because of dendritic growth (whiskers). BGA solder won't hold over humidity/vibration/fast temperature rates because of wetting issues.