For those who have used transformers (including modified microwave oven
transformers) for other projects, making a resistance soldering station
shouldn't be difficult.
Essentially, the xfmr secondary is only a few turns of heavy conductor, and
the primary winding is controlled with a simple (slow) duty cycle control
circuit.

Making a suitable handpiece isn't extremely difficult, the concept is two
electrically insulated contacts that can easily reach between the solder
cups of (many types) of connectors.
A tweezer-type handpiece is the typical style for this type of soldering,
and some thermal resistant insulating material is best for the grips.

Since the output of a properly utilized xfmr will be very low AC voltage
(only about 3VAC), and properly isolated from the AC line voltage,
resistance soldering is very safe and efficient.

The contact arms(?) of the tweezer handpiece are typically heavy gage
stainless steel wire, as it generally resists common lead solders, and
doesn't require constant cleaning to remove heavy surface oxidation.

The principle is that the solder connection will heat more rapidly than the
air-cooled SS arms do, enabling the solder to flow freely without heating
the arms up to soldering temps.
The tips of the arms are typically smaller in cross-section than the arms,
making the most concentrated heat at the solder terminal, and less heat in
the arms.

As far as securing the wires in a connector shell, a glob of hot-melt glue
is probably as effective as filling the shell with something else, and
fairly easily removed if needed.
Potting the soldered connections isn't practical for sub-D connectors (or
many others) since the mechanical connection of many connectors isn't sealed
anyway.

As far as advantages to using solder cup-type connectors, there are rarely
any reasons not to.
If home shop machines are vibrating within the range of destroying soldered
connections any time soon, it's probably dangerous to be near them.

Got a powerful ultrasonic cleaner? Please, let us know the results.

--
WB
..........


"Joseph Gwinn" wrote in message
...

Yes. The problem with crimpers is that there is an immense number of
combinations of terminals, wires, and crimper dies, and one never has
the right stuff, except for those few things that one makes enough of to
be worth collecting a correct set.


It's hard to beat solder cup terminals for one-off projects. I will
mention that with high-density solder-cup terminals, the easiest way to
do the soldering is to use resistance soldering, which allows one to
solder one wire without melting the insulation on the next wire over,
without needing much care.

When everything was inspected, the connector backshell was filled with
polysulfide rubber and allowed to cure overnight, thus potting the
solder joints and gluing the wire insulation to the connector body.

I first met this approach at RCA in the late 1960s, when working on
flight equipment that was literally going to the Moon, and therefore had
to survive the vibration of a Saturn V launch. If it's good enough for
NASA, one assumes that it's good enough for RCM uses.

http://resistancesoldering.com/site/faq

Functional resistance soldering stations pop up on the used market for
pennies on the dollar.

Joe Gwinn