I have some friends that do some serious restoration work on old high end radio stuff like Collins and Hammarlund. A couple of them have asked me if I thought they should stock up on the old Sn/Pb solder while they still can.
Here's an article from 2005 I came across. I was wondering what the status is today.
Leaded is still good for old stuff and hobby/casual use...I have a lifetime stock too... I also have ~60Kg of lead free in slabs recovered from my flow solder machine when I retired if any one wants some cheap...(UK only)
Yes you should stock up on leaded solder, although availability seems fine at present (UK).
A massive amount has been written about the whisker problem, starting about 20 years ago. It didn't really become a big issue, for a collection of reasons.
One is that pin spacing on packages got down to about 0.55mm and then stopped getting closer. The business then went to BGA which has a lot of ball spacing distance.
Another is that for whiskers to grow you need the surface to be stressed e.g. deep drawn cans which were tin plated before the press operation. This is not always the case with electronics.
Another is that some types of tin plating don't show the problem. I don't know the details however.
You also need humidity. In dry air it doesn't seem to happen.
Conformal coatings can prevent it, too.
A large section of industry has been operating under the Control and Monitoring exemption in ROHS. You are this ROHS compliant, via exemption ;) It's quite funny.
The military and medical industries have exemptions. As does "internet switching" (whatever that is).
The chinese stamp "ROHS" on everything including toilet paper rolls, which has made it impossible to police the scene, which works in everybody's favour. A lot of stuff is non compliant. But a lot of stuff cannot possibly be compliant e.g. the Conflict Minerals thing is total bollox (you need to certify that the gold used on your PCBs (made in china) comes from a specific smelter.
If you need to use lead free, the best solder by far is from Almit in Japan.
Postman Pat wrote in news:qt08ii$msq$ snipped-for-privacy@dont-email.me:
63/37 RULES!
Damnit, Janet!
The exemption also allows repairs to be done with leaded solders.
The issue in many cases is flux management and cleaning and what your customer specs in those regards.
Potted and conformally coated asseblies also present repair issues.
Usually it all comes down to complying with what the customer wants.
We had mil spec requisites even after mil spec went away. On specific contracts one does EXACTLY what the contractor want if one wants additional contracts.
Of course, wire solder in Sn63/Pb37 is a worthwhile stock item, but don't overlook the silver-loaded wire solders as well. Surface-mount solder pastes don't store for long times, so the future probably belongs to lead-free regardless of the rear guard action...
Actually some are now much more stable, especially the Chip Quik and MG Chemicals formulations. We have a syringe of the Chip Quik stuff (291?) that has been good for two or three years in the fridge. Just used it last month. Probably not as good as Kester 44 rosin core wire solder, of course.
The US DoD balked at RHOS, and basically forbade its use, to prevent tin whiskers from crippling just about everything. DoD did put a lot of money into research on tin whiskers and how to prevent them, and came to the
hopeless. These systems have design lifetimes in the decades.
NASA has the same issues, and also put a lot into mitigation research:
It may be cheaper but what is the quality actually like? eBay and Amazon
sell unregulated products so you will get all sorts of junk - you have no idea of the actual composition of the solder - the flux could be toxic for example. Unlike Kestor or other name brand sold by brick & mortar businesses, the solder may be contaminated with other metals - perhaps Beryllium - which would not be so good for the person soldering.
You have heard of counterfeit products have you not?
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I buy obsolete components on eBay, but I test them upon arrival, many are counterfeit, but enough are real or serviceable to make it still worth while.
John :-#(#
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Lead free is a RoHS thing originally. Military and space equipment have be en exempted since day one and of course, RoHS does not apply to the US, onl y the EU. Interestingly, another area permanently exempted is devices used in equipment as a "means of transport for persons or goods". I believe th at would include all cars and trucks. So why do they use lead free solder in car electronics?
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Rick C.
- Get 1,000 miles of free Supercharging
Are you joking? Many selling on eBay or Aliexpess would practically kill f or $15. I bought several flash drives recently that are supposed to be 128 or 256 GB for approx $10 and $20 respectively. Not one of them were real and not a 32 GB drive altered to report a larger size. I think I paid arou nd $30 for a real 256 GB flash drive at Costco.
$15 is far from nothing for eBay vendors.
BTW, I always report the frauds and get a refund. The last attempt at Alie xpress only got a $2 refund so I disputed it on the credit card where I wil l get a full refund. So I'll have made $2. lol
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Rick C.
- Get 1,000 miles of free Supercharging
Man, you two really need to get your tinfoil hats upgraded. Some guy in Indiana selling three NOS reels of Kester 44 in original, somewhat battered packaging, and whose eBay store also has slightly-used lampshades and silverware, is _not_ a nefarious criminal mastermind selling poisonous radioactive counterfeit stuff for huge profits from his volcano lair.
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