60/40 vs. 63/37 Solder
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From: GregS on 16 Jul 2010 14:42 In article <6737aa54-c264-4d4f-8dbf-86db5a76ba1f(a)q22g2000yqm.googlegroups.com>, George Herold <ggherold(a)gmail.com> wrote: >On Jul 15, 3:40=A0pm, zekfr...(a)zekfrivolous.com (GregS) wrote: >> In article <7a307a68-f754-413e-8113-4b9d0ce7a...(a)c10g2000yqi.googlegroups= >..com>, George Herold <ggher...(a)gmail.com> wrote: >> >> >> >> >> >> >On Jul 15, 11:42=3DA0am, John Larkin >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> On 15 Jul 2010 08:04:55 GMT, John Doe <j...(a)usenetlove.invalid> wrote: >> >> >> >none given.now (Joe) wrote: >> >> >> >> Why are there these two very similar solders? =3DA0Is there any >> >> >> situation where one is better than the other? =3DA0 >> >> >> >Dunno, but... If you do detail work, try water-soluble flux >> >> >solder. You just wipe off the residue for a sparkling clean >> >> >circuit. >> >> >> And one that makes a great humidity sensor. >> >> >> John >> >> >Yeah, My prototype of a board with several high meg resistors (up to 1 >> >gig.) was put together by myself with old Kester "44" (rosin flux.) >> >Worked great. =A0Production did a few with their favorite water based >> >flux... No good! =A0Now I have to convince them to go back to the old >> >standard. =A0 The new ROHS fluxes seem to be even worse. =A0I measured a >> >few meg ohms between pads that had been 'cleaned'.... NOT. >> >> I had a lot of problems with high Z circuitry. Got under the pads. >> Some boards I had to clean/dry 10 times. In the interim, some of the clea= >ner >> I used got into some caps and started their own circuit mess. >> >> greg- Hide quoted text - >> >> - Show quoted text - > >What kind of flux were you using? I want to try some tests, just >laying down solder and flux gobs on 0805 SMD pads and measure the >resistance. Then cleaning and remeasuring. (I've got a bunch of >other 'fires' that I'm putting out so this may be a few days.) > The boards were commercially made with water based flux. I had to fix them. They actually laid out the boards, which was a mistake. greg
From: GregS on 16 Jul 2010 14:43 In article <i1q2fa$nr9$1(a)news.eternal-september.org>, "William Sommerwerck" <grizzledgeezer(a)comcast.net> wrote: >> I like 63/37 because some stuff I do I like it as low a temp >> as possible. > >Allmost all my soldering is repairs; cold joints seem more likely when >you're fixing something. > > >> Deja vu. I worked for BFEC at NASA site, and went to NASA >> soldering school. I would guess 60/40 would be the norm. > >Probably. I never had to solder, so I never went to school. > >Which site? When? I worked from 1974 through 1978. > > http://zekfrivolous.com/goldstone/
From: William Sommerwerck on 16 Jul 2010 14:59 >> Which site? When? I worked from 1974 through 1977. > http://zekfrivolous.com/goldstone Did you ever change the klystron frequency from the control panel (there were six buttons along the bottom), rather than going out to the transmitter? If so, you used one of the improvements I installed.
From: Robbie Hatley on 16 Jul 2010 15:19 "GregS" recommends for flux removal: > If you can get 95% ethanol, I thinks its best. By the time > you use 98 or 99% it absorbs water anyway on the board, > and you still have a water residue. You can also drink it. And then you accidentally plug the 120VAC into the 5VDC output of a voltage regulator, which promptly explodes and emits flames and smoke, and you just have time to say "oh wow, man, pretty fireworks" before the lights go out and the boss comes storming in saying "What the hell is going on in here? Why is that circuit board flaming like that? Someone grab the fire extinguisher!" Yep, ethanol works wonders, but it's probably not best for job security. I think I'll stick with the isopropanol.
From: GregS on 16 Jul 2010 16:14
In article <i1qa75$p2m$1(a)news.eternal-september.org>, "William Sommerwerck" <grizzledgeezer(a)comcast.net> wrote: >>> Which site? When? I worked from 1974 through 1977. > >> http://zekfrivolous.com/goldstone > >Did you ever change the klystron frequency from the control panel (there >were six buttons along the bottom), rather than going out to the >transmitter? If so, you used one of the improvements I installed. I never ran that, but do recall them tuning them up. Something rings a bell though about mods. As the 80's rolled through everything was remote controled off site. I do remember the time I pushed a button on one of the antenna motors, and everything went black for miles. I also remember the time one would go outside and point at the falling Skylab, and the other person would try to move the antenna and lock on to it. What with the 1 degree beamwidth was impossible. We were using Norads predicts and they were too far off to be able to use. Somebody finally locked onto the spacecraft and finally got good predicts. I also remember the time we tracked the moon with a wrench. For a while. Big 85 ft.antenna made in Pittsburgh, as was much of the stuff made in the USA back then. greg |