Interesting.
I have read that for certain industries (Aircraft, Aerospace) a soldered joint is never allowed. The theory that the stiffness of the soldered joint can lead to a fracture at the point where the wire become flexible again. So all joints can be crimped, shrinktubed and wrapped... but never soldered.
Of course, if the harness is properly supported and anchored down, it seems virtually impossible to get enough movement or vibration to cause a wire failure at a solder joint.... but I suppose in certain applications (like aerospace) there is ZERO tolerance for risk of failure no matter how small.
-G
I think both those thought processes are correct. Solder is harder than the copper, so it can become brittle if it is allowed to bend more than during setup. They key is, don't allow it to bend repeatedly.
The automotive manufacturers don't use solder on wire harnesses, they also don't use any butt connectors or splices, everything is in a sealed connector that's crimped, and those connectors go through a lot of vibration testing to look for any corrosion of fretting, plating issues, etc. When I worked for a supplier we also had to heat up sensors, and then, while plugged in and hot, dunk them in 20 different fluids or solutions, including saltwater, paints, solvents, fuels, etc. The shock of the cold fluid on the hot connector would find any leaks, which would be a fail if it leaked.
They do use solder in fixed objects like sensors, PCB, ECU, etc.
There are people who have devoted their entire careers to solder joints, you wouldn't believe the detail I saw during manufacturing engineering conferences on just the flowing of solder.
The thing I don't like about crimping through the heat shrink, is I don't believe you can get a good crimp, without ruining the seal of the heat shrink. You can get a good crimp, but it will likely compromise the heat shrink, and if you crimp it gently, you can't get a good crimp, but the heat shrink is fine. That's why I crimp, then solder, then heat shrink. But I only create splices where it is supported and not allowed to move during use.
Another difference is they don't normally allow airplane wiring get exposed to the weather as much, although I am sure there must be exceptions to that somewhere on the planes, but even then I wouldn't think it would see any salt spray from the road, though I suppose its possible on the runway. It just seems like everything is more sealed up on a plane than a vehicle that's open underneath.
