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That's interesting. Thanks! (I looked at this one
Atoms in the metal diffuse along the grain boundaries. Who knew? I wonder what the heck drives the diffusion... where's the energy/number 'advantage' that drives diffusion?
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I buy from eBay all the time, I am just dubious about the quality of the
products. I agree that you can get good deals, like your slightly battered Kester solder, but in many cases the stuff (if popular) is just
junk.
Reinstalling my tinfoil hat!
John ;-#)#
I've bought interesting stuff on ebay from antique shops. I guess they got a truckload of odds and ends at an estate sale and don't know what some of it is. Got some nice 30 ga Beldsol wire that way recently. Thermal strips beautifully with the right Metcal tip.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
I love my 11802. It cost a few hundred dollars from ebay. Every 5 years or so, I replace the battery-backed SRAMs in the bottom.
There are other batteries on the boards above, but I've never messed with them.
I wonder if anyone can repair these scopes. I don't think any schematics are available.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
No, China Inc. has the corner on that market. ;-)
The atoms move from areas of higher compressive stress to areas of lower stress, reducing stored energy.
The means of preventing whiskers in lead free has been well understood for quite a while now, and the conversion to lead free has been accompanied by a significant increase in reliability, although one can't prove causality as there were a few other variables changed during the experiment.
Am 16.12.19 um 06:01 schrieb Rick C:
Because you can get some parts lead-free only and that poisons the pot. Mixing metal compounds may get you surprises such as unexpected eutectica, and the few lead-free parts require the high solder temperature anyway.
regards, Gerhard
I buy old rolls of Ersin solder on Ebay. These complaints about fake' solde r remind me of working at Cincinnati Electronics, 40+ years ago. the DECAS inspector on the PRC77 claimed that there was only one brand of solder that met military specs. I told him that he was wrong, and brought in a spool f rom Ersin solder with the required QQ-571 numbers on it. He insisted that i t was fake.
I have used Ersin Multicore since 1966. It was the best, (and most expensiv e) solder available in my area. It wet better than Kester, and didn't have the stronger pine tar scent of Alpha that Heathkit supplied. I bought the .
031" and .062" sizes, until the '90s when I discovered their .015" 'rework' solder.Some shops used Oatey, or other long forgotten brands of really cheap solde r which only came in .093" with really poor flux that spattered everywhere. Some so called techs used 50/50 plumbing solder, which was evident from ru st stains on the chassis.
We shifted to lead free right when ROHS came into effect. We dreamed all kind of bad things would happen, but now the experience is that lead free actually have better durability and overall performance. That is also backed by industry research
Only downside is a little higher peak temperatures
Cheers
Klaus
Did Ersin make multicore with RA flux? Kester 44 and MG 835 flux have a pleasant odor and work very well even on pretty gnarly-looking old parts. I have drawers full of good stuff such as AD639 sine converters, DIP-packaged RF parts, 1990-ish metal film resistors, and so on and so forth.
They're super useful for whacking together small instruments or even larger-scale proof-of-concept demos, and RA flux makes them solder like new.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Been a while, but i think solders with more that 80% lead are RoHS acceptable...
Kester 44 RA is the only way to fly.
hardly
NT
Robert Baer wrote in news:1RWJF.51588$ snipped-for-privacy@fx04.iad:
Just like some with math, you have to get your mores and lesses sorted.
NO lead for RoHS. Don't know where you got your numbers, but I always was told the new euro standard eliminated lead and mercury in particular.
Mil and med in the US have exemptions, but as tin process gets more and more widely adapted in the supply chain, and statistics show better understanding of the factors behind whiskers, it has been more and more accepted and adopted into some segments of those industries. Like in mil realm where COTS is acceptable source. US made is COTS, but most are also RoHS compliant, so the mil boys have to buy products that use tin process.
Robert Baer wrote in news:_RWJF.51589$ snipped-for-privacy@fx04.iad:
Rosin is good stuff with 63/37. Strips a surface clean for solder up real good. REAL good wetting. Real good micro-crystaline structure on a well constructed joint. (that's what *she* said).
in
older remind me of working at Cincinnati Electronics, 40+ years ago. the DE CAS inspector on the PRC77 claimed that there was only one brand of solder that met military specs. I told him that he was wrong, and brought in a spo ol from Ersin solder with the required QQ-571 numbers on it. He insisted th at it was fake.
nsive) solder available in my area. It wet better than Kester, and didn't h ave the stronger pine tar scent of Alpha that Heathkit supplied. I bought t he .031" and .062" sizes, until the '90s when I discovered their .015" 'rew ork' solder.
older which only came in .093" with really poor flux that spattered everywh ere. Some so called techs used 50/50 plumbing solder, which was evident fro m rust stains on the chassis.
ew.
< Yes. Here is an example:Have you ever considered buying a small solder pot to re-tin old components before using them? I used to do it to thousands of salvaged 256Kb DRAM ba ck in the IBM AT clone days, when they were scarce. I was getting boards fr om Unisys for certified destruction that had 144 on each board. I would flo at the boards on the molten solder and run a ling, thin screwdriver under t he IC to loft them off the board. There was slag on the pins, so I would sk in the top of the pot as I used small needlenose pliers to dip the leads in to the solder, then tap the pliers against the solder pot to remove the exc ess. They looked better than new parts, since the wave solder process was d one with 80/20. We sold the ICs for $2.75 to computer stores at a time ther e was almost no supply. I never had one brough back as defective.
The solder pot was all metal,, sitting on a sheet of aluminum. It was groun ded, so with a wrist strap there was no problem with ESD.
I have used mine to re-tin old parts, including some connectors. Dip, tap a nd let cool. I have two Esico 650W for large work, the 70T which is round, and the 75T which is square. I use a smaller (Model 36, 250W ) for leads an d loose parts.
Recycling ICs caused me one problem. I would end up wit a large pile of dro ps and dross around the solder pot. It went into a large can, until it was full. Then I would use a really large pair of channel locks to dump the liq uid solder out of the pot, into an aluminum pan. I would use a wire brush t o clean the layer of crud from inside the pot. It builds up from old flux, and other crud. Once clean, I would fill it wit the droppings and dross, an d melt it back down until it was a little more than full, again. Surface te nsion allowed about 1/16" of solder above the edges of the pot. I ended up with over 25 pounds of clean, solid disks of solder that was used to tin wi res. It was fun, being creative by truly recycling old electronics. :)
Tele Communications equipment is exempt, so it'll be around for a while.
Cheers
There is a separate directive for vehicles, the ELV directive. I haven't read it but it probably says something about lead.
Fun. 144 x $2.75 for probably 20 minutes' work isn't a bad wage. ;)
I've considered a solder pot but it has never seemed like an essential--my protos are mostly hand-wired, and with RA flux I never have a problem with them. We're failing the cat test really, really badly at the moment.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Chris Jones wrote in news:mq3KF.8236$ snipped-for-privacy@fx33.am:
RoHS applies worldwide, including the US, idiot! It was adopted around the world. If you are a commercial manufacturer and you want to sell your products anywhere in the world, you have to be in compliance to do so. The UE will not even allow non certified products through their customs.
The US has exemptions for military and medical products BECAUSE at the onset of RoHS nobody knew just how bad, if at all, the whisker issue and other problems (higher temps) would cause. A duly diligent examination of the problem would take a good ten years or more. We are there.
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