Message-ID: <01BDEF1C.60075D20.ed@testelectronics.com>
From: Ed Armstrong <ed@testelectronics.com>
Reply-To: "ed@testelectronics.com" <ed@testelectronics.com>
To: "Lancair [Lancair.List@Olsusa.Com] (E-mail)" <lancair.list@olsusa.com>
Subject: Solder or Crimp??
Date: Sat, 3 Oct 1998 22:22:57 -0700
Organization: Test Electronics
Mime-Version: 1.0

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Angier wrote:
I've always understood the conventional wisdom to be that crimping 
connectors to stranded wire is best in a high vibration environment since a 
soldered joint may fatigue and break eventually.

Angier is right, soldered stranded wire is weak at the point where the 
solder ends and the strands begin. This is a fatigue point. The solder 
holds the wire stiff until this point, consequentially, all flexing is 
concentrated at this point. Now I do not know which is best. To have this 
fatigue point, or to leave it unsoldered and have a place for moisture to 
wick into and possibly fail with temperature cycling and vibration when a 
couple strands loosen. If you solder the joint, you could minimize flexing 
at this weak point by covering it with heat shrink. The inner melt type. My 
main concern when suggesting soldering was to avoid corrosion. Moisture 
seriously wicks up into stranded wire and stays there. Then, corrosion 
takes place very quickly especially on the positive wires where 
electrolysis makes oxygen. A little corrosion can loosen the crimp, and the 
wire will pull right out. There is grease to help retard wire corrosion. 
The FAA might have some rules about this. I will try to look it up.

Regards,
Ed