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Comment by djmips | Hacker News Reader

Does anyone know the the risk is for electronics hobbyist?

Don't lick your boards, wash your hands before you eat, and if you're really concerned, wear gloves while handling solder wire.

The smoke from soldering isn't lead - a soldering tip is (if it's not literally glowing into the yellows) far, far too cold to vaporize any lead from solder - you need to be 1500+C for it to start being a problem, and you're not soldering that high. It's rosin smoke, and if you're in doubt, leave your iron in a puddle of solder - it shouldn't smoke, it should just sit there liquid after the initial rosin has burned off.

The rosin smoke isn't great, but it's not a lead toxicity issue.

Your concern is lead on your hands from the wire, and then eating afterwards without a good scrubbing. I don't think it will penetrate your skin, but you could always wear a pair of gloves if you wanted. There are some shooting sports soaps that are designed to help really rip any lead off your hands, so you might use one of those if you're concerned.

Also, afaik, there's no reason for hobbyists to not always use lead-free solder. But of course that doesn't mean something you're taking apart used lead free.

Repairing an old device that used leaded solder is a reason to use leaded solder (even new leaded solder during the repair). I don't even use the same tips across leaded and lead-free solder.

I think pretty much all consumer electronics uses lead free solder for the last 10+ years. The reason hobby users tend to use leaded is it's much easier to work with and they don't care about health or the environment that much.

The leaded solder melts easier than non-leaded. This is good because you are way less likely to burn off traces or melt the board using a lower temperature iron. I only use leaded solder because I suck at soldering.

A few years back spent a lot of time stripping lead paint using a heat gun and IR emitter thing ("silent paint remover"). It was definitely smelly, but I convinced myself that the temperatures were far too low to vaporize lead.

But in the back of my mind I always wondered if there was an equivalent of a eutectic mixture for the liquid/vapor phase transition.

There are. They are usually called azeotropes. For example water and ethanol form an azeotrope, though the difference isn't as drastic as with metals.

Soldering doesn't get hot enough to make significant lead fumes (although flux fumes are also bad to breathe). The main risk from lead solder is from cleaning your soldering iron. Both the common techniques (damp sponge and brass wool) make many tiny balls of solder. They can be hard to see, and because they're round and dense, they can travel much farther than you expect by rolling and bouncing. They can get caught in clothing, and from there potentially fall into food.

I don't personally use lead solder for this reason. If you have a good temperature-controlled iron then SAC305 is almost as easy to use.

I typically use lead-free solder unless I'm dealing with some annoyingly massive thermal mass like a joystick anchor, but I use the same rule whenever I'm dealing with solder, fishing weights, and ammo: wash hands before they go near my face after handling lead products. Inorganic lead is not readily absorbed through the skin (that's not to say it cannot be, or never is), so generally speaking as long as you avoid ingesting it (hence wash hands after handling it) there's little to worry about.

Unless you're dealing with electronics made prior to 2006, almost all of what you'll be soldering with is lead-free. Thank the EU's RoHS directive for that.

[1] https://en.wikipedia.org/wiki/Restriction_of_Hazardous_Subst...

There's a lot of argument that lead-free solder isn't as good (or easy to use) and several hobbyists still use leaded solder.

Have you ever tried the lead free stuff as compared to a good 60/40 or something like that?

It's horrid to use. And the lead-free stuff is far worse in manufactured equipment - how many devices have failed early due to BGA solder joint failures that basically didn't exist before RoHS requirements? I think the nVidia 8600M issues were traced to that, and plenty of other BGA equipment since 2006 or so has failed rather early.

It's only horrid when the flux it comes with is crap. Most people try the cheapest garbage they can find on Amazon, and that's the problem.

I use Chipquik SAC305 with water-washable no-clean flux core and I actually prefer working with it over Sn63Pb37.

Yep, I was around for that shitshow with two laptops. Soldergate was annoying but to be honest there haven't been any similar issues at scale I'm aware of, as the issue was identified and fixed.

Solder comes in many different alloys. Some of them are really terrible. However some of the better ones are pretty good. Spend some money to find a good one. If you can find a manufacture they often have a lot of data and will tell you which is good for what. Often bad solder is great for some purpose, but that purpose may be something not useful for you (you probably don't need the maximum strength joints as one example), cheap while still working is useful at industrial scales, but odds are $75 of the most expensive solder will outlast your lifetime so why cheap out?

Your hobby really isn't worth breathing lungfuls of leaded-solder fumes. Manufacturing is done by robot, not you sitting over a desk (said as someone who was doing this till I realized it myself).

Lead-free solder can be a bitch to work with for some projects due to the higher melting point, and I do keep a spool of leaded wire around for that reason - but generally speaking for most hobbyist uses it's a non-issue as long as you have a relatively modern iron that can output enough heat (and retain it).

Yeah, a good iron and wire with a decent flux core helps a lot. Lead-free solder will never melt like butter the way leaded does, but I solder with it fairly often at work and it's not a show-stopper by any means.

Flux in general is probably the most important right after making sure you have an iron capable of handling the thermal recovery (you can't get the shit to stay liquid long enough if your iron can't handle keeping temp). The difference between relying on the flux core in even my leaded solder and adding a tap of my MG Chemicals flux when making a joint is night and day.

My lead-free joints come out nicely rounded and shiny just like my leaded ones with some practice and the right consumables. But I certainly have to break out hot air station more than I would when using leaded solder to deal with larger thermal masses (and why I will still break out my spool of leaded wire on rare occasion when I'm working with temp-sensitive components and just want it on the freaking board).

Yeah I use lead free for some stuff. I have switched back to lead for finer work since it just behaves better. Seems like the sweet spot for lead free is very small - too cold and you get a weak dome connection, too hot and it doesn't want to leave the tip.

Not nitpicking but solder for military and public transport applications is exempt and still used, due to better performance under vibration and shock.

Was hired as a software engineer at a tiny company, in April of this year, that produces surveillance cameras. They had me building and repairing their cameras which involved a non-trivial amount of soldering. They never told me I was handling lead and I wouldn't have known if I wasn't a curious person but it turns out they thought lead-free solder "sucked" and wouldn't switch.

considering almost all of this is in poor countries i'd say you are low risk if you solder infrequently and always have good airflow. that said there's no safe level of lead so wear a properly fitted p100 respirator if you want to be as safe as you can be.

None if you use quality lead-free solder.

Unfortunately lead-free solder is a lot harder to solder with; it just doesn't flow as nicely. Companies doing it in an automated way have long figured it out though.

This is why hobbyists are often still using leaded solder, particularly outside of the EU. But also in the EU, because it just flows so damned nice.

That's not actually true though.

I find SAC305 to wick into joints faster than leaded solder does, provided you have quality flux in the solder.

If you get the cheapest lead-free solder you can find on Amazon it will be bad.

Doubly so if you have a non-temperature-controlled soldering iron. Too cold, and it won't melt effectively. Too hot, and exposed metal will oxidize rapidly.

What is your favoured temperature for let's say through hole DIP connections?

650°F or 340°C.

Works beautifully with SAC305.

provided you have quality flux in the solder

which you often don't need with leaded solder.

Yes, you need slightly better flux to avoid using toxic heavy metal in your hobby electronics.

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