Homebrew_PCBs

Read-all-about-it;)

Just hit my inbox.

<http://www.safeworkaustralia.gov.au/sites/swa/about/publications/pages/review-of-hazards-and-health-effects-of-inorganic-lead-implications-whs-regulatory-policy>

<http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documents/871/Review-hazards-health-effects-inorganic-lead-report.pdf>

4.2.3 Dermal absorption
Dermal absorption of inorganic lead compounds is negligible (ATSDR 2007, US EPA
2006). Few studies have provided quantitative estimates of dermal absorption of
inorganic lead in either humans or animals. Those that have been conducted
consistently show the absorption to be negligible for both soluble and insoluble
lead compounds.

> 4.2.3 Dermal absorption
> Dermal absorption of inorganic lead compounds is negligible (ATSDR 2007,

US

> EPA 2006). Few studies have provided quantitative estimates of dermal
> absorption of inorganic lead in either humans or animals. Those that have

been

> conducted consistently show the absorption to be negligible for both

soluble

> and insoluble lead compounds.

And tells you to wash your hands afterwards.

It's not saying anything new, we all know chewing on the solder is a bad
idea.

Tony

Hindsight has an arrogance that’s rather fascinating…



Phasing out lead in paint & fuel was probably one of the best moves ever. Lead ingestion makes you stupid, and it affects kids a lot more than adults. Just what the world needs – more morons.



It only been 50-odd years that just how toxic lead is was shown, and it’s removal from products started. It really is a recent event – how soon we forget & trivialise it.



And who opposed the phase-out? The oil companies…



An unexpected result was a drop in crime (some claiming 50% in certain areas), as well as a few less dead kids: http://www.un.org/apps/news/story.asp?NewsID=40226. “Ridding the world of leaded petrol, with the United Nations leading the effort in developing countries, has resulted in $2.4 trillion in annual benefits, 1.2 million fewer premature deaths, higher overall intelligence and 58 million fewer crimes…”



That’s a big teapot you’ve got there…



We should put up a few statues of this bloke: http://en.wikipedia.org/wiki/Clair_Cameron_Patterson.



Tony







I Agree,

all the screaming about the dangers of lead based solder is just a

" tempest in a tea pot,"

The uproar started with the suspicion that lead based paint chips had caused mental retardation in some poor children..

There are many studies however, that show that there are few if any hazards associated with the use of lead based solder.

Simply handling solder is certainly not hazardous as long as the user remembers to wash his hands after using it and before eating.,



I do however question the health aspects of inhaling the rosin fumes. I use a small fan to suck the fumes away from my face and a HEPA filter to trap any particulate.

Works great even when using a torch to solder parts together or using a solder pot and dipping wire leads.

.

I have also noticed that the "non-lead" variety of solder has a tendency to crystallize after just a year or two and develop high resistance and "noisy" joints!

Maybe that is why so much of the equipment made in Europe, Japan or China tends to fail after a few years of operation..



Dan



"Everything that glitters is not necessarily good." Anon.

On Fri, Jul 18, 2014 at 9:12 AM, 'Tony Smith' ajsmith1968@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:



> 4.2.3 Dermal absorption
> Dermal absorption of inorganic lead compounds is negligible (ATSDR 2007,
US
> EPA 2006). Few studies have provided quantitative estimates of dermal
> absorption of inorganic lead in either humans or animals. Those that have
been
> conducted consistently show the absorption to be negligible for both
soluble
> and insoluble lead compounds.

And tells you to wash your hands afterwards.

It's not saying anything new, we all know chewing on the solder is a bad
idea.

Tony












[Non-text portions of this message have been removed]

On 19/07/14 09:35, Peter Johansson rockets4kids@... [Homebrew_PCBs] wrote:

>
> On Fri, Jul 18, 2014 at 6:21 PM, David Lyon david.lyon.preisshare@...
> <mailto:david.lyon.preisshare@...> [Homebrew_PCBs]
> <Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs@yahoogroups.com>>
> wrote:
>
>> No, our Government only now discovered what the Romans figured out 1800
>> years ago.
>
> The Romans poisoned themselves with the lead salts they added to their wine,
> *not* the elemental lead they used for their plumbing.
>
>> Give them time to come up to speed with technology, please.
>
> Please spend some time studying your history and chemistry.

It is said that romans used to chew on elemental lead for the sweet taste, which
also caused poisoning after a long time.

Hello--

At a recycling center where I volunteered, a manufacturer dropped off
several gaylords full of electronic scrap, including a batch of thick (1/8")
circuit boards assembled with lead-free solder. The boards had failed
final test and were discarded because they couldn't be reworked due
to through-hole pullout. I found that while I could salvage individual
components, I invariably ruined the board, and I suspect that factory techs
had the same experience.

If the intent behind adoption of RoHS was the reduction of electronic
waste, I wonder
how much of the waste stream now consists of unrepairable lead-free-soldered
products?

Getting the lead out of gasoline likely made much more of a difference
in the overall
lead burden than removal of lead from solder.

73--

Brad AA1IP

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

> At a recycling center where I volunteered, a manufacturer dropped off several
> gaylords full of electronic scrap, including a batch of thick (1/8") circuit boards
> assembled with lead-free solder. The boards had failed final test and were
> discarded because they couldn't be reworked due to through-hole pullout. I
> found that while I could salvage individual components, I invariably ruined the
> board, and I suspect that factory techs had the same experience.
>
> If the intent behind adoption of RoHS was the reduction of electronic waste, I
> wonder how much of the waste stream now consists of unrepairable lead-free-
> soldered products?
>
> Getting the lead out of gasoline likely made much more of a difference in the
> overall lead burden than removal of lead from solder.
>
> 73--
>
> Brad AA1IP

Just used leaded solder to repair them, it works. You'll need to use a higher temperature due to the lead-free needing it. Technically not ROHS compliant, but who's to know?

Not all lead-free solders are the same, and early alloys (& methods) had a few problems like you've found. Seems to have been sorted out these days (and yes, even the whiskers).

Tony

(1/8" PCBs? Lots of layers? Thick boards suck up lots of heat, unsoldering anything is a hassle)

1/8" are always more difficult to work with.

Regardless of solder, there are vast differences in through-hole
plating adhesion between different board manufacturers (and possibly
batches).
I believe it has to do with de-smear (where the epoxy is etched out of
the hole to expose some glass fibers) and possibly the hole activation
and plating itself.

Sure, the process window narrows with lead-free. It requires better
tools and more skill to rework without damage.

You are most probably right, leadfree solder will not nearly have the
benefit of unleaded gasoline, simply because lead in fuel was so much
worse.
For unleaded gasoline we still don't know the full picture, for
example only now after many years we see clear statistical links
between a marked reduction in crime and the phasing out of leaded
gasoline.

ST

On Sat, Jul 19, 2014 at 3:25 AM, Brad Thompson
brad.thompson@... [Homebrew_PCBs]
<Homebrew_PCBs@yahoogroups.com> wrote:

> Hello--
>
> At a recycling center where I volunteered, a manufacturer dropped off
> several gaylords full of electronic scrap, including a batch of thick (1/8")
> circuit boards assembled with lead-free solder. The boards had failed
> final test and were discarded because they couldn't be reworked due
> to through-hole pullout. I found that while I could salvage individual
> components, I invariably ruined the board, and I suspect that factory techs
> had the same experience.
>
> If the intent behind adoption of RoHS was the reduction of electronic
> waste, I wonder
> how much of the waste stream now consists of unrepairable lead-free-soldered
> products?
>
> Getting the lead out of gasoline likely made much more of a difference
> in the overall
> lead burden than removal of lead from solder.
>
> 73--
>
> Brad AA1IP
>
> ---
> This email is free from viruses and malware because avast! Antivirus protection is active.
> http://www.avast.com
>
>
>
> ------------------------------------
> Posted by: Brad Thompson <brad.thompson@...>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> ------------------------------------
>
> Yahoo Groups Links
>
>
>

So the one shop was full of old bald guys who had lived much longer due to the health benefits of the fumes? ;-)

Seriously, while we may not always understand the full extent of our stupidity a bit of common sense usually saves your ass.
I mean we evolved that way - to survive without having all the facts.

Is it good to breathe solder fumes if they make your throat sore? Probably not.
Same goes for breathing the smoke from burning tobacco plants or drinking ethyl alcohol, do you really need the government to tell you that's a bad idea?

ST

On Sat, Jul 19, 2014 at 3:01 AM, 'Tony Smith' ajsmith1968@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

Years ago a friend mentioned he used to visit two assembly shops where they hand soldered; one used extractors, one didn’t.  At the shop where they didn’t vent the fumes they were all bald…  Hmm…

 

Tony

I'm a 70 years old electronics engineer.
I'm not a smoker, but my pulmonary X-ray image suggests to my doctor
that I'm a smoker (darker image).
Is that the lead vapors or what?
If lead, is there any way to get rid of that, please?
Cristian

Lead doesn't vaporize at soldering temperatures, you'd need 1700°C for
that, so it's unlikely.
Also, most inhaled lead (mainly from lead dust) is absorbed into the
blood, it doesn't stay in your lung.

ST

On Sat, Jul 19, 2014 at 9:15 AM, Cristian crissstian@...
[Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

> I'm a 70 years old electronics engineer.
> I'm not a smoker, but my pulmonary X-ray image suggests to my doctor
> that I'm a smoker (darker image).
> Is that the lead vapors or what?
> If lead, is there any way to get rid of that, please?
> Cristian
>
>

On Sat, Jul 19, 2014 at 9:15 AM, Cristian crissstian@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

> I'm a 70 years old electronics engineer.
> I'm not a smoker, but my pulmonary X-ray image suggests to my doctor
> that I'm a smoker (darker image).
> Is that the lead vapors or what?

As you are 70 I suspect you are a victim of your time. So secondary cigarette smoke inhaled when it was acceptable to smoke in the restaurant or bar or office, in the UK we also burnt coal and had smogs, car exhausts were less clean, and we had factories that made things, and also burnt coal to fuel their energy needs.

> If lead, is there any way to get rid of that, please?

Not lead, but it could be flux fumes. I don't think other than a lung transplant there is any thing you can do. Sorry...

> Cristian
>
>

Dave
G4UGM

On 19/07/2014 02:25, Brad Thompson brad.thompson@...
[Homebrew_PCBs] wrote:

> Hello--
>
> At a recycling center where I volunteered, a manufacturer dropped off
> several gaylords full of electronic scrap,

Several gaylords? Sounds like a different way to do it :-)

I've been using unleaded solder for a while now, after the initial
problems (basically due to having a cheap crappy soldering iron, and
bits that would dissolve, and probably the earlier unleaded solder alloy
just wasn't the same as it is now) I've been soldering with the stuff
for years now. I no longer have problems with crumbling soldering iron
bits, I can get it to flow nicely, and I've assembled hundreds of boards
with the stuff with the same soldering iron bit and it seems to be
working now just as well as the old lead solder.

The only problem I have with unleaded soldering is unleaded solder
paste. I used to reflow all my SMD stuff with a hot air gun but this
just doesn't seem to work right now (certainly temperature related) so I
just hand solder SMD stuff now (and now I've had to do it for a while,
I'm getting much better results by hand soldering SMD than I used to get
with leaded solder paste and reflow)

Nah, all young-ish guys (30-40’s).



Correlation may not equal causation, but it does suggest strongly “look over there…”.



And on smoking, King James I of England wasn’t a fan: “…a custom loathsome to the eye, hateful to the nose, harmful to the brain, dangerous to the lungs, and in the black stinking fume thereof nearest resembling the horrible stygian smoke of the pit that is bottomless.”



In 1604 !!



The full text is here: http://www.laits.utexas.edu/poltheory/james/blaste/blaste.html, he really hated tobacco & smokers.



Truly, the human race is a slow learner.



Tony





So the one shop was full of old bald guys who had lived much longer due to the health benefits of the fumes? ;-)

Seriously, while we may not always understand the full extent of our stupidity a bit of common sense usually saves your ass.
I mean we evolved that way - to survive without having all the facts.

Is it good to breathe solder fumes if they make your throat sore? Probably not.
Same goes for breathing the smoke from burning tobacco plants or drinking ethyl alcohol, do you really need the government to tell you that's a bad idea?

ST

On Sat, Jul 19, 2014 at 3:01 AM, 'Tony Smith' ajsmith1968@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

Years ago a friend mentioned he used to visit two assembly shops where they hand soldered; one used extractors, one didn’t. At the shop where they didn’t vent the fumes they were all bald… Hmm…



Tony






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[Non-text portions of this message have been removed]

I would worry a LOT more about the ingredients in the flux than about the lead. That smoke you see while you are soldering and that homes in on your nose and mouth like it has the world's most accurate guidance system, is not the lead. It is the flux or some of it's ingredients. And heaven only knows what is in there. Do use proper ventilation, but primarily for the flux, not for the lead.

On the subject of the lead, just where does it come from? The twilight zone? Er, well no. We mine it from the ground. I fail to see why it is so bad to put it back there, with due cautions, of course. Or recycle it: I believe we have methods of recovering the materials from circuit boards. I think we have problems that are a lot more pressing than what these environmental fanatics are constantly making us waste our money and time on. And their methods usually produce more "pollution" anyway.

Paul A.

> On the subject of the lead, just where does it come from? The twilight zone? Er, well no. We mine it from the ground. I fail to see why it is so bad to put it back there, with due cautions, of course. Or > recycle it: I believe we have methods of recovering the materials from circuit boards. I think we have problems that are a lot more pressing than what these environmental fanatics are constantly
> making us waste our money and time on. And their methods usually produce more "pollution" anyway.
>
> Paul A.

I do believe your cunning plans require a little more thought, sparky.

Tony

Most commercial solder fume extractors use activated charcoal filters.
I guess it depends what you need to keep away (particulate, volatiles, etc..).
There may be regulatory requirements on the level of worker protection and a furnace filter may not always meet them.

If the room is large and the soldering minimal a simple fan without any filter drawing the fumes away from you works fine.
Dilution is the solution to pollution more often than not.
As someone mentioned the smoke tends to home in on your face, it has to do with the air currents created by your body heat and breathing.
The fan needs to be slow and larger diameter, any strong draft will interfere with soldering.

Many production places vent outside the building rather than use filters.
Depending on what you make downdraft benches with perforated metal tops can work out better than hoods or elephant trunks.

Also there are vast differences between flux types, some bother me much more than others.

ST

On Mon, Jul 21, 2014 at 8:20 PM, Daniel Donnelly KC7VDA@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:

  My stepfather solved the problem for under $15.00, He put a box fan  with a furnace filter on my bench ... end of problem. No expensive fume hood needed.