Cordless soldering irons, wire splicing Options

[vitamin914]

I have mostly used soldering stations (Metcal and Hakko) that have adjustable temperature controls. Great for benchwork, not so much when you are upside down under the dash.

Weller, Milwaukee, Hakko make some battery powered units and Ive seen some no name butane powered irons. None seem to have much in the way of good temperature control. Twenty years ago I had a butane micro torch / soldiering iron - didn't like it at all. The solder would oxidize in seconds (dross up) and I was forever trying to keeping it clean no matter how low I kept the flame. Put it down the wrong way and the exhaust port would burn the table. I did like the micro torch tip for shrinking heat shrink tubing but that was about it.

Anyone have experiences with newer cordless soldering irons - battery or butane?

[vitamin914]

This is great info and this is why I asked. Even though I asked about soldering irons, this was not hi-jacking the thread by offering better solutions. It was obvious why I wanted to ask about the irons. If there is something better than soldering why not do it?

I am only familiar with the Thomas & Betts Sta-Kon type crimp connectors. I did not know the rollover type were generally available. The rollover clamping onto the insulation gives lots of strain relief. (thank you for those links Superhawk)

I always thought that soldering was better to reduce the contact resistance of the joint. I agree it does make the joint brittle in that the strands are fused and cannot flex by sliding past each other. This makes it stiff and prone to fatigue failure ESPECIALLY at a termination where it is fixed from moving on one side. I don't think that it is as critical in the middle of a wire where both sides of the joint can move together. This is probably where the difference of thought comes from. I have to splice in some new turn signal wires going to the bulbs so I thought soldering and heat shrinking the mid wire connections was the way to go.

So from a vibration/motion, with an automotive wire perspective, crimp never solder near terminations but soldering mid wire is generally ok since it less likely to fail provided both sides either float or are clamped from movement?

I will need to invest in some new crimp tools and crimps...

[Superhawk996]

I always thought that soldering was better to reduce the contact resistance . . .

This is a common misconception about crimped connections. Again, there are white papers out there that back the position that a crimped connection offers less resistance than soldering. Allow me pull up a good summary of why this is:

"At a first glance, it might seem like soldering provides a lower resistance than crimping. Surprisingly, reality differs. A properly crimped connection actually creates a metal-metal colloidal bond at the surface between the wire and the terminal. This makes it effectively gas tight, stopping oxidation inside the joint. The copper-on-copper connection is generally superior to solder considering that most solders have more resistance than copper.

In practice, the difference in resistance between either methods (properly done) is beyond the accuracy range of average multimeters. Hence, the difference is negligible, especially when working on 12v circuits. By that my point is that soldering will not provide “better conductivity”.

https://millennialdiyer.com/articles/motorc...rimp-or-solder/

To a large degree this is observable in the crimped terminations so familiar on our beloved 50 year old relics. Unless they are artificially corroded by salt exposure, you'll find most of the OEM crimped terminations are still 100% serviceable and do not show high resistance (i.e. voltage drops) across the various crimped connections in our cars.