Re: Solder vs. Crimp

[DeWitt Harrison <de@aztek-eng.com>]

On Mon, 10 May 1999 15:52:46 -0400 Huw Powell wrote:

>a similar assertion popped up (re: crimping making the metals "one") in
>some stereo rag years ago.  curious, I queried my metallurgist dad.  his
>answer: they're blowing smoke (or inhaling it).  it would take very high
>pressure/temp to achieve this, far higher than soldering.  basically you
>would be welding without a welder...
>
>The only drawback I can think of to soldering is the solder wicking into
>the wire making it stiffer near the connector.

The crimping process is not welding, it is the creation of a clean, 
gas tight joint between metal surfaces. The "gas tight" aspect is
the key to the reliable performance of good crimp joints as corrosion
at the interface is thereby precluded. The pressure required to
form a gas tight joint is, in most cases, beyond that produced by
simple single action crimp tools.

In the case of  stranded wire, especially when insulated, it is an
unavoidable consequence of the soldering process that flux is wicked
up the wire along with the solder and remains there. Even mild fluxes
create an electrochemically active environment in which the tin/lead
solder is the sacrificial alloy against copper in the galvanic series.
Just add a little humidity and you have a recipe for corrosion.
In the airframe business they call it various technical names like
"white crud."

As satisfying as a well done solder joint can be, we have testimony
here that the US armed forces, the FAA, Audi and Phil Payne all
state that crimped wire joints are the preferred/required joining
method in vehicle wiring harnesses.  I think that does it.

End of grump.

DeWitt Harrison
Boulder, CO
88 5kcstq