Leaded solder.

[Dave Plowman (News)]

Don't do much soldering, then? ;-)

BTW if it's multicore, the flux deteriorates with time.

[The Natural Philosopher]

I can, but it needs a huge amount more attention to get a halfway decent result, and I am still suspicious that the joint will - as Tony pointed out - fail later due to the intrinsic properties of the alloy.

You have to clean better, flux better, support the joint properly as it cools, and be very precise on the amount of solder and the exact heat of the joint. In short everything is several times more critical. That isn't so bad in production, but its a nightmare for hand soldering. we had all sorts of troubles with trying to use low lead soldering alloys on a wave soldering machine as it was, but in time, once the temperature and flux levels were adjusted, we managed.

Its like banning rubber soled shoes, and then dictating that everyone run in clogs, which end up being sprung with springs to take the jarring out. The solution is worse than the problem it was supposed to solve.

When I were a prentice, twas at Marconis, and the procedures they taught were the results of over half a century of lead soldering in critical avionics applications. There simply isn't that depth of lead free soldering experience available yet. Which is why its still not mandated for specialised kit of high criticality.

The appalingly stupid business off banning it in solder, whilst leaving millions of tonnes in batteries, and on church rooves, is just an example of more pressure group knee jerk bollocks we have come to expect from weak minded ineffectual left wing knee jerk governments in Europe.

[Tim Streater]

Not much these days, no. I did a bit when I got this 68000 single-board computer a few months ago. They leave you to decide how you want the interrupts hooked up, so once I figured out what I needed in terms of the clock and serial I/O chips, I then patched the board to suit. I can see that I no longer have the manual dexterity of 20 years ago, though .

I dunno if this stuff is multicore, it's very thin. But I do have some multicore that's prolly more than 25 years old.

I often tin the wires when wiring a mains plug but not much else. The soldering iron the bro gave me 50-odd years ago packed up last year, too.

[Skipweasel]

Shouldn't do that. The normal screw onto copper is relatively stable, but solder is a) too soft and b) corrodes, both of which can lead to a loose and therefore hot connection.

[Tim Downie]

I used to do that but not any more. I think tinning the wires removed their "elastic" properties and renders the tinned end of the wire "plastic". Consequently, the connection is more likely to loosen & overheat.

I could be wrong and my explanation may be b*llocks but I think you'll find it's not recommended.

the other Tim

[Andy Dingley]

Six-sigma generally means really large scale production, where cost cutting in production over-rules everything else (except legislation).

So your products are presumably cheap consumer electronics, where lead- free solder has become shorthand for "crap on the customers, they'll only have to go and buy another one".

[Andy Dingley]

...and it'll be 18 swg, not 22

[brass monkey]

Rubbish. You just don't know how to solder properly.

I should do, for a year or so (45 years back) I was soldering maybe 30-40 joints a minute, all day, every day.

[docholliday]

22SWG? Still using the thick stuff, then... I'm currently using mostly 24 or equivalent, with 0.4mm (between 26 and 27) for the really fine stuff

[Skipweasel]

22SWG is just right for the soldering I do - that's why I have a reel of it I bought - er - twenty years ago!

[D.M.Chapman]

Hah, common fault on the philips monitor that often shipped with Amigas.

1084 IIRC. Flyback transformer needed resoldering and it came back to life. Had two. Both had same problem :-)

Darren

[andrew]

I suspect that the reasons for removing lead were to do with disposal at end of life rather than exposure during use. Lead probably affects stack clean up after incineration and almost certainly ends up in water draining from land fill cells ( but not necessarily in ground water if this leachate is dealt with well).

The big hits must have been removing lead from petrol, paint and water pipes in soft water areas.

AJH

[Chewbacca]

I fully agree the stuff is crap, but batteries were exempt because there is so much lead it will be recycled (good value) but with a few solder joints it is not cost effective so can easily end up in landfill etc. But I do hate rules taken to extremes, solder could easily have been managed.

[Bob Eager]

That'll start another discussion!

[BartC]

That's pretty slow. I remember seeing women (in the pcb assembly factory I once worked at) soldering rows of IC pins; the soldering iron moved almost continuously from one pin to the next.

They seemed to use a particular kind of solder too; when I asked them to do a one-off job for me, I requested they use my solder (some multicore stuff), which they complained of as being smelly. All around 25 years ago so none of this lead-free.

[Chewbacca]

And they used proper rosin flux as well. Good cleaning power, but best washed off the pcb afterwards, and the best stuff for cleaning - Freon. Banned as well, but this time for a good reason.

[Tim Watts]

Tim Downie ( [e-mail]) wibbled on Monday 28 February 2011

17:53:

2 things happen for the worse:

a) Solder is fairly malleable so under compression it does not "spring" much to retain compressive forces, but moves out of the way leading to the joint loosening over time.

b) Where the solder binds the copper strands togther, the abilitity of the strands to slide is inhibited wich forms a weak point proned to bend fractures. What's more, is due to the wicking action of solder, the point of rigidity can be a fair few mm away from the bit you actually tinned, which is often the part that you want to try to bend afterwards to lay the wire down in the housing.

a) is more of a problem for the scenario described. b) tends to be more of an issue on small wires subjct to movement.

The correct method, if you must, is to crimp a ferrule on the end but it is not necessary for big wires in plugs. I've done this for RCBO where the neutral and functional earth wires are often super finely stranded for flexibility (which doesn;t suit the huge terminals they have to go into) and ELV cables on my downlighters where I used a high temperatue silicone wire (very fine wire is difficult to get into a regular terminal without strands going everywhere).

Cheers

Tim

[Tim Streater]

True but I've not found them to loosen. Where I've screwed the screw down tight, the solder's moved away a bit and left an indent.

I'm aware of the wicking issue but not found that too much of a problem either.

Are there ones which are small enough? The reason I'm doing this in the first place is I got fed up with twisting the wires round to form a bundle, and then finding as I tighten the screw that either the end of the screw cut some of the strands, or that some of the strands were pushed sideways and so were not caught under the screw, and were in fact loose in the fixture. No chance of them moving out and shorting, I don't suppose.

A ferrule would need to be quite small for a 13-amp plug, seems to me.

[brass monkey]

You're quite right, I was guessing at 30-40. I just soldered a row of imaginary pins and it's prolly more like 80+. Whatever, I wish I had a penny for each one :D At one point I was thought to have lead poisoning from soldering. In hospital I went for a weekend to have jabs in the bum every few hours with some very thick gunge. Not to worry, they had mixed up my samples with someone else and didn't expect the gunge to have any nasty side-effects. NHS eh? And they actually seemed to care back then.

[Tim Watts]

Tim Streater ( [e-mail]) wibbled on Monday 28 February 2011

22:13:

That's at the medium end - they go fairly small (0.5mm2) upto 6mm2

These are the ones I use:

(scuse wrap)

Ideally you'll need the correct crimp but I dare say pliers will suffice, for the smaller sizes at least, as, unlike typical usage of crimps, these will be further squished by a screw anyway.