Fun with Lead-Free soldering

Chris Carlen wrote in news: snipped-for-privacy@news1.newsguy.com:

YUK! Proper anti-static and QC procedures must not exist in your shop.

So they'll just throw away anything not working ?

For starters, solder with lead will continue to be available for maintenance reasons as I understand things.

Several industry sectors ( telecoms, servers and networking gear ) have negotiated an 'opt-out' and will continue to use solder containing lead. I believe this is since they made a case that their equipment can't be made reliably with lead free soldering methods.

Stand by for more exceptions when the s*it fits the fan.

The whole thing is a bureaucratic balls-up.

Graham

snip

I have,over the past couple of years, tried nearly all the alternatives to lead-free solder, and not one of them come near the flowing and wetability of good old 63:37. IIRC, a bismuth based one was about the best of a bad pack.

The EU directives only apply to those things "Put on the market" (Euro-bollocks-speak for "sold") Hobbyist, experimental, and DIY users are unaffected. It's a funny directive, if you are not covered specifically by it, you are exempt. Then, there are general exemptions for military, national security, national telecom infrastructure, and IIRC, medical implants. ie, anything that's damn important has been exempted by the Euro-fools, too scared of anything going wrong. Then article 5(1)(b) allows for an application for exemption to be made, and a number of these are in the pipeline. The rumor has that the TAC (Tech advisory Committee, those that do the directive's bidding) are going to be pretty hard-nosed on these.

The latest bit of Euro-stupidity is them having a talk-fest about the amount of lead permitted in chandeliers. So when was the last time you saw of those being tossed into a land-fill ??? My nephew spent about 2 years looking for one for a historic home, and then he got gouged on the price. Silly boy, he should have just got one free from the Euro- landfills that are obviously brimming with old chandeliers

Barry Lennox

Hello Chris,

Eating at the lab desk? That sure doesn't sound like a proper work place procedure. I mostly work in medical electronics. If the FDA ever saw someone have a burger at a work station I bet they'd lock down the whole company. Actually I am pretty sure they would, and for good reasons.

Even here in my consulting practice there is strictly no eating in office or lab areas. Never.

Other than that, what about the chemicals in the ketchup on a burger?

Regards, Joerg

That's one of the problems with the "no clean" stuff. It isn't very good flux.

My office is my lab. I eat in the lunch room.

(My emulator has to be hooked to the proto type and to a PC. This either means I need two PCs or have the lab in the office. They knocked out a wall to make the space large enough.)

If chemicals are needed to clean a PCB, I take the PCB to the fume hooded PCB cleaning area. I don't bring those chemicals into the office/lab.

I think a more expensive solder for hand work will become available. Chances are it will be an alloy of plutonium, goofium and unsidaisium and hence be as toxic as all get out but it will be lead free.

Hello Ken,

Like driving the devil out with Beelzebub. This all reminds me of MTBE that they hastily used to oxygenate California gas to make cleaner air. It drops a car's fuel efficiency by about 10%. What an achievement. Then they found out it pollutes the ground water. Big time. But it was kind of too late.

Regards, Joerg

You forgot the Unobtainium ! ;-)

Graham

Hi Joerg, I've heard in passing of this MTBE but never understood what it was all about. Care to eleborate ?

Incidentally, I reckon that bio-fuel is the long term answer to oil shortage / demand / price issues, not to mention reducing greenhouse gases. I gather that there are a number of pilot schemes that are actually fairly big now that are showing interesting results. Ford is selling a version of its Focus in Sweden for example that'll run an a 50/50 mix of straight petroleum fuel and alcohol. The alcohol is made by 'brewing' timber waste. For some reason I don't yet understand, unlike Brazil's gasohol, this mix actually provides 10% *more* power than straight unleaded ! Sounds great to me. The hydrogen fuel idea is plain bonkers in comparison.

Graham

MTBE is now recognized as bad-assed stuff, bad for the environment and doubly bad for humans... it's going to be phased out in Arizona, IIRC, beginning this winter.

...Jim Thompson

Yes, it's a catalyst (natch), so it doesn't get used up. The housing rots and the platinum/rhodium thin film is still there.

Best regards, Spehro Pefhany

it was

MTBE was the cheap alternative to using ethanol. The ethanol producers (or at least the corn producers) were the source of the lobbying funds to get the superoxygenated gasoline mix legislation passed. The west coast refiners squawked at the impending cost increase, so MTBE (which can be made in the refinery) was the compromise.

Presumably, if the gorund water were polluted with ethanol, fewer people would be complaining.

I read somewhere that is either is now, or soon will be, economic to sweep the dust off the freeways and recover the platinum out of the catalytic converters from it.

Probably urban myth.

I say urban myth,

Especially since the ceramic beads or ceramic honeycomb that is used in catalytic converters, have a coating of catalyst which is only a few micro inches thick at best. This may amount to a few square feet at a few micro inches thick of platinum in a large converter. Converting to metric, gives a block of platinum about 1 cm by 1 cm by 0.3 mm, or about 0.03 CC's, which is about 0.64g worth. Not much, especially considering that very little is likely to leave the converter. A replacement catalytic converter costs around $150 CND for a typical unit, proving there can't be much precious metals in side.

I had a spec sheet on my desk for some lead free. It was bragging about a lower then most other lead free solder melting temps, and I think reasonable wetting. I was wondering what they used to lower the melting point, since the usual alternatives are ether expensive (indium), or much more toxic then lead. Reading the spec sheet it was alloyed with a little cadmium.

Hello Graham,

I am not a chemist. All I know is that it increases oxygen in fuel and raises the octane level. It supposedly burns cleaner. Even though I have a car that adjusts the combustion process to the fuel quality in realtime I can see a notable drop in fuel efficiency between in-state and out-of-state gas. About 10% or so. Also, this boutique gas is a lot more expensive than gas anywhere else.

MTBE has the unwanted side effect that if gas leaks from old storage tanks it pollutes the ground water. So the politicians who had hastily mandated the stuff then hastily mandated that all gas stations change their tanks to double-walled. Of course, much of that was water under the bridge by that time.

Yes, but unfortunately all those efforts take place outside the US. There isn't much here. I have seen bio diesel engines operate in the

Running on timber? People had figured that out during and after WW II already. Huge barrels were strapped to cars to make "wood carburetors" because there just wasn't any other fuel available.

AFAIK you need natural gas to make it on a large scale. Looking at the rapidly rising natural gas prices over here that hydrogen strategy doesn't make much sense to me.

Regards, Joerg

Hello Jim,

Here in CA they are replacing it with Ethanol. Which means we will still have boutique gas at elevated prices.

I don't think politicians will ever understand that you have to have a reliable fast train system to drag people away from their cars. I'd use the train to the Bay Area but not right now where you never know when it really arrives. And that thing crawls like a snail compared to the trains overseas. So, everybody hops into their cars or a rental to do the 2-3 hour trip.

Regards, Joerg

Talk about jumping out of the frying pan into the fire. One of the explanations of the name for Antimony is 'anti-monk'---because it killed monks who worked with it. Lead is positively benign compared to Sb.

Talk about a coincidence -- I opened my Merck Index to look up the LD50 for lead, and the first page (out of over 2000) opened was lead!!!

Interestingly, soluble antimony vs. lead compounds appear to be more acutely toxic by weight:

antimony potassium tartrate: LD50 = 55-65 mg/kg in mice

lead acetate: LD50 = 200 mg/kg in rats

Perhaps rats are a bit more robust than mice :-)

However it is lead that is a far greater chronic toxin with lead poisoning considered to be serious in children at 0.44 ppm or 44ug/dl blood concentrations.

Lead is also considered to be a carcinogen, and antimony not, or at least not as well established as Pb.

Note that Sn95Sb5 is the solder alloy now approved for potable water systems, whereas all Pb solders are banned from such use.

So the 0.5% Sb in CASTIN doesn't concern me much.

Some more interesting stories and info about carcinogenity:

Well RoHS says you can't use that either !

Next .... ?

Graham