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Comment by djmips | Hacker News Reader

I still wonder about all the hobbiests, including occasionally myself who might not be treating leaded solder with the caution it deserves. I use unleaded solder but I also fix older gear.

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Metallic lead isn't especially bioavailable.

Lead in paint is not metallic: https://en.wikipedia.org/wiki/Lead_paint

You don't use solder in a place where it's exposed to friction (like window sashes with lead paint) which makes a dust, nor do you put it places where it's exposed to food or drink (again, hopefully) like with pewter or lead glass (crystal).

Lead compounds that are formed from common reactions between metallic lead and other compounds are, on the other hand, incredibly bioavailable, and very common

I concur. Recommending unleaded software to hobbyists makes people irrationally hostile. I have a theory of why...

I know you’re joking, but leaded solder is significantly easier to work with on a hobbyist level.

As long as you’re washing your hands properly and avoiding contact contamination it’s not an issue.

I’m always amazed when I see people using lead-free solder for “health reasons” who then inhale all of the fumes from their flux, though.

It's significantly easier if you have grossly inadequate soldering equipment.

This is 2025, you can get properly temperature-controlled soldering irons for dirt cheap now.

Temperature control isn't usually the real problem, it's insufficient power to heat the board up to the liquidus temperature of the solder. This is an especially annoying pain in the ass when you're desoldering components from a board with non-thermal relief pads connected to gigantic copper pours, where you basically have to either use hot air or a board preheater.

I run a hobbyist open source hardware project that is user-assembled (PhobGCC) and even though our early boards had bad thermal relief a basic Pinecil is good enough to desolder SAC305 or SN99.

But most of the issues with soldering came from people using uncontrolled irons that were either too hot, instantly burning off pads, or too cold thus not letting the flux punch through the oxides.

When you get to big copper fills, SN63 helps, but ChipQuik helps more. So does a Thermaltronics TMT-1000S which is coming next month at $125.

(love my TMT-2000S but the 1000S looks to be a steal)

Leaded solder in electronics is not a significant source of human exposure. In jewelry, maybe, but it's unusual to use it there, and in plumbing.

For most people or specifically among those who touch electronics for a living?

Even among those who touch electronics for a living. There are occupations that do get significant lead exposure (as the article points out), but electronics technicians have never been among them, even before fume extractors were common for soldering. Metallic lead is sufficiently hard to oxidize that even most people with lead bullets embedded in their bodies don't get lead poisoning, and, at soldering temperatures, lead's vapor pressure is not sufficient to reach a toxic dose, even taking into account lead's horrific tendency to bioaccumulate.

You can mitigate the risk: set up a good extraction filter and wash your hands when you finish work.

Extraction fans have nothing to do with it. You don't get lead gas or floating particles in the air when you're soldering.

Solder is not the problem, soldering fumes do not contain vaporized lead as that would require >400C. They might and often do contain vaporized flux/colophony/resin. You reaaaaaaallllyyyy dont want to breath that thus fume extractors are a must.

Agree with this but also want to stress the importance of washing your hands after handling solder, to be sure. And any affected surfaces in your work station / area.

You don't want to accidentally ingest tiny bits of lead from the solder, and this probably goes for solder without lead too.

one of my soldering irons regularly glows cherry red hot when under usage. So far past 400 C. I don't use that every time I solder, but sometimes I do

That being said, I think the impact of the lead may be tiny compared to the rosin fumes. The real issue is someone in a factory who may handle leaded solder ever single day. The accumulated exposure over a lifetime is a big deal

There's something extremely wrong with that iron. I've had a Tenma soldering station to that once, caused by a bad thermocouple that was lying to the controller.

thermostat burned out not longer after I bought it. Good iron design, bad thermostat design. It works great for soldering pipe and bar stock together. Don't leave it plugged in for very long.

Solder is absolutely a problem. The life cycle of your part doesn't just include when you solder it. It includes anyone who has to handle it in the future, and it includes the E-Waste dump in an impoverished country that it inevitably ends up in.

Not really, metallic lead is pretty inert. Its lead compounds and lead dust that are dangerous.

recycled PCBs are often turned into dust.

Not just due to the Pb dust though, also Al, Fe, Cu, fiberglass:

"Mineralogical analysis of dust collected from typical recycling line of waste printed circuit boards" https://www.sciencedirect.com/science/article/abs/pii/S09560...

Yes and Cu and fiberglass and the resins are especially toxic too

I have a big spool of lead solder probably from the 1980s and I store it like treasure. It’s so much better than modern solder.

You can just buy SnPb solder today, probably with better fluxes than whatever they were using in the 80s. Non-Pb solders also work fine for almost everything (I keep a little bit of SnPb around but do most of my work in lead-free), the big thing is to have a good iron and good tips. Makes way more difference than the solder composition.

I have good news for you. Leaded solder never went away. It’s still available.

Modern solder and fluxes are also likely to outperform 40 year old solder.

You can still buy brand new solder intended for medical/mil use made in Europe/Poland by Cynel

https://www.cynel.com.pl/en/?view=article&id=99:sn60pb40-pro...

Fun fact - Rambo knows his stuff and uses Cynel sn60pb40 https://www.youtube.com/watch?v=q3XRrPZRJEw&t=11

Solder spatters everywhere even if it's not vaporized. The resulting lead-bearing powder gets everywhere.

This is especially true of hand soldering. Hand soldering requires regular cleaning of the soldering iron tip. Both the common methods (brass wool and damp sponge) produce many tiny balls of solder that roll and bounce easily. They can end up caught in clothing then fall into food.

I wonder how much lead a solder sucker aerosolizes.

It doesn’t.

The fine coating of solder dust on my workbench suggests that you are wrong.

How do you know the dust is solder?

How is the solder getting out of the sucker? Let alone turning into a fine powder?

How much desoldering are you doing??

There are far more likely sources of particulate matter, such as flux which we know does get aerosolized.

This is just an anecdote, but I know someone who worked with leaded solder since he was a young teen, and he sometimes holds the solder in his mouth(!) when working on tricky joints. He is in his early 90s now and still very healthy.

working on tricky solder joints in your NINETIES is kinda wild on its own!

I suspect there are far more people like that, and we just don't hear about them because they keep to themselves. This Youtuber is an exception: https://news.ycombinator.com/item?id=40519095

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