More on lead-free junk solder

A 200W combo, UK made 2002, with one solder joint to a small on-end
electrolytic failed
so could be just due to vibration/resonance.
But it is on a board with obvious conical solder joints so perhaps the most
likely inherently weak joint to fail first. The larger (heatsinky) joints
are shiny and conical, redone by hand with junk solder maybe, but all the
other small joints look horribly grey. On the other board all conical joints
but all bright silvery colour. What is the consensus of the panel - redo all
the grey joints with Pb-Sn solder and leave the bright ones, or if it aint
broke - don't poke. ?

 

Have you checked for zinc migration?

I have no idea if that is still common, but I have some older 70:s and
80:s stuff where this happens on some connectors and switches that
appears to have been of incompatible material.

 

There are some very nice silver-bearing electronics solders out there
that do not fail under stress.

http://www.all-spec.com/1/viewitem/KWLF24555/ALLSPEC/prodinfo/w3path=cat

Comes to mind. It ain't cheap... I have used it with success, with
specific reference to R/C submarines... stressful conditions, high
dampness, vibration, several amps on the connections and considerable
heat.

Failing that, 63/37 tin/lead solder is your best bet, and my tipple of
choice for my normal (vintage radio/audio restoration/repair) uses.

Peter Wieck
Wyncote, PA

 

I really can't make my mind up on this. All the regulars on here know my
views on lead-free solder, and I must admit that I am inclined to go over
lead-free joints that look *particularly* suspicious, with //proper//
solder, but as I've said here before, there are two schools of thought on
this among the metallurgical experts as to whether mixing lead-free and
leaded solder in the same joint, produces one with long-term compositional
stability.

Add to this that now the full legislation for RoHS is in place, as UK
repairers, we are fully obligated, officially under threat of EU law, to
repair equipment originally constructed with lead-free solder, and placed on
the market after July 2006, using *only* lead-free. This means that by
reworking a lead-free joint on such an item with leaded solder, we are
officially inviting the wrath of the solder police, and I guess, prosecution
for what they are now calling an " eco crime ".

I haven't heard of any such prosecutions yet, but in these days that we have
now where people are getting prosecuted and heavily fined for (
accidentally ) putting the wrong type of recycle waste in their household
bins, I'm sure that the day can't be far away when some poor engineer gets
tricked into breaching the legislation, by some over-zealous trading
standards person ...

Arfa

 

Are you sure about this? My understanding is that leaded joints can
still be repaired with leaded solder.

Ian.
--

 

Read a bit more carefully - that's " lead-free " ....

Arfa

 

Oops! I misread that. Sorrrrry.
Ian.
--

 

No probs, Ian. You are right, of course. For those not familiar, the
situation is that any equipment 'placed on the market' before July 2006,
irrespective of what technology has been used to manufacture it, may be
repaired by any technology that you see fit - ie by using leaded or unleaded
solder. However, common wisdom is that if it was manufactured in lead-free,
then it should be repaired in lead-free, likewise for leaded manufacture,
used leaded solder. However, it is getting impossible to buy new components
now that are not lead-free, which //may// mean that their legs have been
dipped in a lead-free solder ...

Some manufacturers, notably Sony, have insisted for several years now, that
all of their official service centres use only lead-free to repair *all* of
their products, irrespective of original manufacture technology. The service
bulletin that was sent out by them regarding this, actually caused
considerable misunderstanding in the UK repair industry, with regard to what
was the correct legal situation. I am of the opinion that you should
probably not mix solder types if at all possible in a joint but, like most
reading this I suspect, I just can't help myself when I come across a bad
joint in a place that I know is not going to be reliable if reworked in
lead-free.

Equipment placed on the market after July 2006, must have been manufactured
in lead-free, and the directive says that we must not compromise this, so
must use lead-free solder and RoHS compliant components to effect any
repairs. The exception to this, is where an equipment has been granted an
exemption from the directive. Such equipment includes avionics and medical
and some military equipment. This will have continued to be manufactured in
leaded solder, and marketed quite legally. Repair of such items can - and in
my opinion *should* - be effected using leaded solder.

Arfa

 

If the manufacturing date is not on the back of a bit of kit needing repair,
then presumably its a matter of saying you cannot repair anything made in or
after 2006 , then asking the owner when he thinks it was made, and then
making the appropriate comment.

 

As you say, this is one of the difficulties, and where a typical piece of
euro-mumbo-jumbo, however well intentioned, comes unstuck for lack of being
properly thought through in terms of the poor sods who have to be
responsible for its implementation at the sharp end. In years gone by, date
of manufacture was commonly stamped inside the cabinet, or on the chassis.
Now we're going to have to rely on our abilities to read component date
codes, or plastics moulding date clocks in the back covers.

I have, however, started to see the legend "PBF" or "PbF" appearing on
PCBs. Whilst I accept that this doesn't necessarily mean a build date ( or
marketing date ) of post July 2006, it does at least confirm what we might
already suspect just by looking at the dubious grey joints on the board, and
in theory, if only for the reason that no-one is really sure of the
long-term effects of mixing solder types, it would indicate that we should
be using lead-free to repair it.

At the end of the day, all of this is just another way to make our lives
unnecessarily complicated for no well-defined reason. For many years, my
wife owned a childrens' day nursery. It got buried in more and more and more
layers of rules and regulations until the whole day was spent in writing
reports, and trying to avoid breaching any childcare guidelines, or worse,
actual legislation, much of which was at best unnecessary and obstructive,
and at worst, total euro-nonsense. Eventually, like many independents, she
gave it up, and sold it to one of the big chains, who now dominate the
childcare business, and are the only ones who can afford to employ the legal
people to make sure that they are complying. I can see us independent repair
agents being driven out of our businesses over the next few years for the
same reasons ...

Arfa

 

Lead-free solder joints do look grey. And they have poorer resistance to
vibration induced failure AIUI.

If you use Sn-Pb solder to repair a board with PB-free you're *breaking the law*
and Mr Lead Free Man may come along and fine you £5000 !

Graham

 

Zinc ?

Graham

 

Correct. He said 'lead-free'.

Graham

 

Hi Graham. Agreed on the vibration thing. As far as the 'breaking the law
bit goes, only if the equipment was " placed on the market " post July 2006.
Equipment prior to that date *can* be repaired totally legally using any
type of solder and components you like, *even* if it was originally
constructed using lead-free and RoHS compliant components ... RoHS
compliance, and maintenance of that compliance, is not required or
enforcable on pre-July 2006 equipment.

Arfa

 

Yes.

Some connectors and switches have been made using material (brass?) in
which zinc may migrate from the pin into the solder joint, and form a
ring of isolating zinc oxide. Using a magnifying glass one can see a
thin grayish ring on the otherwise perfect solder joint.

My old Apple Macintosh plus had this problem in the deflection circuit
where it would lose vertical deflection.

Resoldering the joint gave it a few more years before it happened
again.

I also had a preamp with switches that suffered from this problem.

Thomas

 

Is this a leadfree product??? leadfree does not always look shiny and
good. older formulations are not as good as todays.
Hand soldering leadfree is an art form. Untrained workers that used
lead products does not mean they know what they are doing. Must be
retrained. I have been in manufacturing for 25 years and with
leadfree its a bitch.

 

The pillocks that came up with this law obviously know nothing about
electronics. I call on all servicemen everywhere to defy this stupid
legislation as it is unworkable. Stock up with with as much leaded
solder as you can and USE it! Screw the rules, I say.

 

Pillocks indeed. It is an ill-thought-through piece of legislation intended
to protect the environment from a threat which many of us believe did not
exist from lead in its solder form, in the first place. It is a typical bit
of euro-nonsense, but unfortunately, this "save the planet" hysteria, whilst
being laudable in principle, and absolutely fine if applied with common
sense, has now taken on almost the mantle of a religion, with green as its
god, and anyone who goes against it is branded as a worthless heretic.

There are now euro-zealots in just about every local council, who pursue
people through the courts for incorrect recycling or 'fly-tipping' for
putting their garbage bins out on the footpath a day early, or placing stuff
beside a locked bin at their local recycling centre and any number of other
ridiculous things that I read about in the papers just about every day. It
even now has its own name - "eco crime", and the perpetrators are "eco
criminals".

So, whilst I agree with you 100%, I'm not sure that I want to become the
first person to be pursued, persecuted, and ultimately treated to a £5000
fine, possible prison, and a criminal record, for using the 'wrong type' of
solder. Like it or not, I guess that we've got to just follow the rules,
until someone a lot more powerful than us, manages to prove that the whole
thing is a pile of gonads. Otherwise, one of us is going to finish up like
that poor greengrocer guy that stood up for his right to sell loose bananas
to little old ladies, in pounds and ounces, and finished up pursued,
villified, prosecuted and imprisoned, until the poor sod had a heart attack
and died. Just this week, his stand has proved that it can be worth it, as
the euro-crap which was going to force this ban on us totally from 2010, has
now been dropped. But I for one, don't want to test the dubious strength of
my heart, from the stress that would inevitably result from taking on these
people, do you ?

Arfa

 

Fortunately we now have the power of the internet. Pester the MPs with
emails. Pester the "Greens" pester anyone you can think of. Email the
newspapers. Tell everyone that this bloody madness has got to stop. I
WILL NOT USE LEAD FREE SOLDER. This is not a "green" issue, its an
electronics reliability issue. All the extra new equipment being
produced to replace the failed stuff because of crap joints, not to
mention houses burning down is NOT the way forward. Its time we put
these legislative bird brains in their place. The revolution starts
now!

 

It appears that the reason for relenting was because they realised that
this could affect trade with the USA who, of course, still use the
imperial system (even if the do get some of the measurements wrong), and
wouldn't accept things labelled only in metric. It's a long time since
we had something to thank the Americans for.
Ian.
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