The examples you gave are (mostly) not subject to mechanical stress.
I'll bet I could pull apart YOUR soldered (only) wire joint. I'll bet my CAT
could probably pull apart your soldered joint. Heck, your soldered wires
would probably fall apart out of shame.
I'll further bet an insane ostrich couldn't pull mine apart.
On 11/29/2010 5:12 PM, email@example.com wrote:
Well it just happens to be that NASA prohibits a mechanical connection
before soldering it. It makes it too difficult to repair. I'd imagine
there is a bit of vibration, but the connections hold just fine.
In avionics, in general, soldered connections in a wiring harness
are FORBIDDEN. Crimped connections only, thank you very much. Soldered
connections must be supported against vibration for a distance in both
directions from the joint. Perhaps in space where gravity is not an
issue things are different.
On Nov 30, 1:11 am, firstname.lastname@example.org wrote:
So, what is it? Are they forbidden or are they forbidden if not
supported? I know they aren't totally forbidden because I know that
when an instrument is installed using a plug type connection, they
solder the wires to the plug.
Hank <~~~ confused
On a cannon type connection with strain relief, soldering is allowed.
On a cannon type connection with no strain relief, the pins are
crimped, and ONLY crimped.
On a Sub D type connector the same is true. If the connector is
soldered, the cable MUST be solidly affixed to the chassis of the
device or the tray within something like 2 inches - I'd have to dig
out the actual specs.
So generally, soldered wires without support are definitely forbidden,
and soldered connections with support are frowned upon - proper high
pressure crimps are preferred.
If the lead is short enough that the prevailing vibration frequencies
and their resonances are both high enough and low enough to make it
impossible for the components to be induced to vibrate and flex the
wire to cause fatigue, no problem, I guess.
I was always taught when populating a board with discrete,
through-hole components, to put the little hook in the lead to locate
it the proper distance from the board and to hold it relatively
securely in position for soldering. All the higher end contract board
assemblers around here always did that as well.
Lots of electronic manufacturing around here - home of RIM,
Electrohome,ComDev and a raft of other high-tech electronic companies
over the years - now more of the "silicon valley north" computer geek
You have inspected millions of solder joints. I won't dispute that.
What were these joints on?
On circuit boards you are correct - and I stated that.
What kind of joints between 2 wires do you inspect that do not have a
mechanical connection component other than solder? On what?
Educate us please.
If they were not joints between 2 wires, what kind of joint were they?
( am assuming we are on target here and they were electrical
connections - although even most (although certainly not all) tinwork
has some crimping involved before soldering)
Wiring onto terminal strips GENERALLY involves a "hook" of some sort
on solid core connection wires.
I'm not saying you are wrong and I'm right - I'm just asking what
connections, and what kind of connections, on what, do you consider to
be adequate with no mechanical component to the connection other than
ALL the high end speaker equipment I've worked on has had the wires
bent around the tabs on the speakers. Most of the junk chinese stuff
I've had to resolder has not - - -
I was taught to twist lap, at the very least, and "western union"
joint every soldered splice before soldering and taping, or heat
schrinking, a joint, and to heat shrink at least half an inch past the
joint in both directions on 18 guage wire. A bit less (proportionally)
with decreasing wire guage. (for vibration/bending protection)
I guess as long as it's better than the chinese, and not too much more
expensive - but it's still not "best practice"
In mnost cases that is definitely correct. I will, on occaision, po]ut
a spot of solder on the terminal end (where the wire end comes
through) but it has to be a quick shot, not allowing ANY solder to
wick to the outer end of the crimp. Sometimes required for corrosion
protection (to keep fluid or corrosive gas from "wicking" up the
conductor) and always combined with a good heat shrink sleave on the
If you can GUARANTEE you always make a perfect joint, and it will not
be subjected to undue vibration/stress, in theory the joint will work.
Tensile strength of 60/40 solder is 6400 lbs, shear is 5700.
Tensile strength of 63/37 is 6700, and shear is 6060.
In comparison, drawn copper wire is 12,500 and rolled is 32,000
None of your applications are particularly "safety" items - like
aircraft wiring and even automotive electronic control wiring.
For your applications, solder without independent mechanical
connection appears to be "good enough" - in most of my applications
it is NOT.
Best practices for soldered electrical joints involves a mechanically
secure joint which is THEN soldered to assure a permanent low
resistance electrical connection.
I've had a few of them over the years - and yes, a professional
temperature controlled soldering iron works real nice - and on 4 and 6
layer circuit boards they are highly adviseable. But a cheap, old,
well-used and well-tinned iron can do the job ALMOST as easily if you
are doing onesy-twosies on single or double layer boards with
reasonable sized traces.
Don't try fixing SMT stuff with it though. (I've done a fair amount of
both - board level repairs on American Megatrends motherboards back
when my eyesight was good enough to handle it, as well as repairing
old tube radios, and a whole lot in between)
Would I love to have a good temperature controlled soldering and
desoldering station on my bench? You bet! But the boss isn't paying
for them today.
Not for electrical soldering. As to cleaning, sanding, filing, etc.
a lot depends on the tip itself. Good electronic soldering tips
should not be filed as the plating in place, will no longer be
there. For electronics tips, use, as someone said, a wet sponge.
If the tip is really corroded, use a bunch of paper towels folded up
and wet with water, and then scrub the tip on the paper. This works
a little better than the sponge. Also, you can gently scrape the
tip with a knife for even a screw driver to remove some of the
oxidation. I have a small tin of electronic flux (I've had it
sooooo long that it was about 15 cents on the stick-on price tag)
which I will occasionally dip the tip into. This helps clean it up
also. Also, temperature regulated irons keep the tip cleaner by not
cranking the temp so high that oxidation occurs rapidly.
I do, it's usually the main component of tip cleaner. Another thing
that works well is either a copper or stainless steel pot scrubber.
I have a tip cleaner I got from Radio Shack years ago that is cone
shaped and has a compound that cleans a hot tip, it is used like
a pencil sharpener, I believe it contains sal ammoniac.
On Mon, 29 Nov 2010 17:01:40 -0600, The Daring Dufas
Sal Ammoniac, (Ammonium Chloride) when heated, breaks down into
Ammonia and Hydrochloric Acid.
Definitely not good stuff to have around electronic circuit boards.
If you use it on your soldering iron, be sure to rinse the iron to
dilute/neutralize/remove the acid.
On 11/29/2010 9:23 PM, email@example.com wrote:
That's what the wet sponge is for. A little tray in my 40 year old
Weller temperature controlled soldering station. I have some 40 year
old tips for it that are still working fine. I bought it new and have
replaced a few parts over the years but it ran 8-12 hours a day for
years when I was doing bench work with few problems.
40 seems like a lot, but now that you mention it, those Weller irons are
workhorses. Tips lasted a long long time and you could replace whatever
part needed it. I have some vague memory of needing a new "body" every
dozen years or so. Never had more than a WP25, maybe the temp control
lasted longer! The Ungars were terrible.
When I accidentally dropped the iron on the plastic case, it melted
a grove in it and Weller replaced it at no charge back in the 70's.
I replaced the heater element once and of course several tips but
that's all. The soldering station is still working like new. The
replacement for it has a sponge tray and iron holder that can be
snapped onto either side of the transformer housing.
I think I have the next model up, "Weller EC 2001" adjustable and with
digital temperature readout. Great tool! It's over 20 years old and
there were many times it was on 8 hours a day. I think I replaced the
whole heater and cord once, lots of tips.
My old Pace solder sucker went through a lot of heaters, the second one
I bought is much better, (Pace ST115) I think it's been about 8 years
with no problems. I love to desolder a 40 pin IC and have it litteraly
fall out of the board.
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