From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] To solder or not to solder, that is the question
To: lml
Date: Wed, 17 Jan 2007 23:31:49 -0500
Message-ID: <web-1766405@logan.com>
In-Reply-To: <7141427652BB3049A7DBF1084B67805B0F7B66@penumbra.arilabs.net>
References: <7141427652BB3049A7DBF1084B67805B0F7B66@penumbra.arilabs.net>
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Posted for "Kevin Stallard" <Kevin@arilabs.net>:

  Hi Guys,
  
  
  
  I've watched with interest the posts arguing that soldered connections can 
be
just fine.  However, as with things that are written, it is difficult to put
things in the context all of the time.
  
  
  
  My point of reference is that from connectors.  The response from Fred I
think is the closest to where I was directing my remarks.
  
  
  
  I believe the original poster indicated he wanted to service is panel easier
and was thinking about using connectors to make both the testing, integration
and maintenance of his panel easier.  And that therefore, connectors were in
his future.
  
  
  
  I will do the same.  I want to test my rig on a bench and be able to remove
the panel and work on it on a workbench rather than in cramped quarters of my
airplane.
  
  
  
  Later, another poster indicated that advice he received was to solder
everything.  "The best/most reliable connector is a good solder joint-or no
connector at all"  was one of the remarks.
  
  
  
  I just don't agree with this.  Modern aerospace quality connectors and
contacts are extremely reliable and robust.  The issue I have is with the
termination of wires to connectors.
  
  
  
  Wires to connectors with solder just don't work for me.  From my own hard
experiences with wire harnesses (automobile, military, and hobby projects),
the things that used to bite my in the rear get me over and over and over (and
over) again are:
  
  
  
  1.	Soldering wires to anything.  I could always count on them breaking.
  2.	Cheap crimpers.  You know those pliers looking crimpers with the red
handles and colorful assorted connectors.   They are truly evil ;)  I would
either smash the wires so hard they would effectively cut the wire, or so
loose the contact would just slip off.  Sometimes I would get a good crimp.
  3.	Heat on connectors has impaired the reliability of connectors I've wired.
  
  
  
  The only strain relief that ever worked with solder and me was epoxy.  Every
thing else breaks far too easily, and even that didn't work well at times.
  
  
  
  I later bought a bunch of ratcheted crimpers at one time (some surplus 
stuff)
and researched and found the connectors that are used with them and I have had
nothing but delight in my connectors and crimp jobs.  Yeah, I spent over
$1000.00 on crimpers and contacts.  Have you ever wished you could just buy
happiness?  This is one case where I did.
  
  
  
  One of the biggest headaches that I've had is getting strain relieved wire
harness put together that could survive the installation process.  Using
proper ratcheted and calibrated crimpers and expensive contacts have all but
relegated this problem out the window.
  
  
  
  I am now consistently good with the wire harnesses I build.  They take a far
better beating when they are being installed, removed, installed, removed, and
installed again.  I don't melt the connector or the insulation and more
importantly, I've stopped burning my fingers!
  
  
  
  There are lots of other advantages with working with crimped sockets or pins
and a separate connector shell.
  
  
  
  1.	It is much easier to fix pin out mistakes
  2.	You don't have to worry about getting the connector too hot when putting
the wires on
  3.	If you mess a pin or socket up, you don't have to throw away the whole
connector and start all over again.
  4.	You aren't therefore tempted to use a large and complex connector that
should be in the trash because you don't want to solder it all over again.
  5.	You don't burn the other wires next to the joint you are working on.
  6.	You only have to use the number of pins that you actually need, making
identification of the connector easier (by looking at the pin patterns)
  7.	The whole process of assembling your wire harnesses is faster as you can
sit down and mechanically crimp pins on to your wires.  It's great using
calibrated expensive crimping tools because you don't have to think about it
as much as you do when soldering.  Most everything self aligns.
  
  
  
  The only solder I'll use on a wire harness are those solder filled heat
shrink tubing used to splice wires together.  That I can install with a heat
gun....
  
  
  
  I don't consider using solder cups on connectors or solder anywhere else.
  You can strain relief all you want, but the bottom line for me is that a
proper calibrated crimper and quality contactors are a more robust connection
to start with.  They are more serviceable, take a better beating during the
installation process and for me, much easier to service and maintain.  Add
strain relief on top of that and life is good!
  
  
  
  Rather than saying Solder is Bad, I should have said that I have suffered
much mental trauma, emotional "shear points" and back and neck "stiffness"
from using solder on connectors.  On the other hand I have found much "strain
relief" and happiness in using good, expensive calibrated crimping tools on my
wire harness projects.
  
  
  
  Now back to work....
  
  
  
  Kevin
  
  L2K-291