Rich wrote:

The arguement that I've heard about NOT soldering is that by soldering
you create a hard connection that is subject to stress from vibration.

Nonsense. Aerospace manufacturers use solder cup terminals on critical
connectors throughout aircraft and spacecraft which operate in severe
vibration and environmental conditions that you would not survive.

However, my practice is to solder ALL connections and also heat shrink
over them as well. I can't imagine any on-board connections that
would be affected by vibration except perhaps on an engine harness.
Personally, I would solder them too.

Waste of time and solder if the terminal is designed for crimping it
provides adequate mechanical support and electrical connectivity.

I believe that advantage of soldering is that you completely fill any
voids in a terminal or lug thus making it impossible for salt
water/air to penetrate and cause corrosion. Heat shrinking over the
connection further protects the connection.

Buy the cup type crimp connectors and do the same thing, they are sealed
at the connection end.

It would be interesting to know what the mil-spec requirements are
that our navy uses for their ships. I worked in that industry, but
was not involved in cable wiring so I am not familiar with the spec.
Maybe someone knowledgeable in this mil-spec will chime in.

There are pages of mil-specs. Each one is for a particular application.
Some are for mechanical crimps, some are for soldered connections.

In answer to your question whether proper mechanical crimping with an
adhesive heat seal is enough, I think that it meats the minimum
requirements. But I think that soldering before the heat shrink is
better.

If the crimp connector is sized for the wire used and the crimping tool
is a high quality (not stamped out sheet metal held together with a
cheap rivet) of the proper size and type for the connector used, no
soldering is required.

Rick