MCR
Veteran Member
Somehow I feel like I've typed this before, but here goes:
Properly done crimping is fine. Properly done soldering is fine.
The problem is: What defines "properly done"?
I guarantee you that VW not only specifies which crimper to use for each crimp, they actually verify the process doesn't wander by replacing dies on a schedule or periodically sending crimped components to a metallurgical lab.
Unless you use the tool recommended by the crimp vendor, and match it with the correct number and size of the conductors (that is, say, 2 wires of 14 gauge), then you really can't be sure.
Same thing with soldering. You need to be able to verify (usually visually) that the soldering is done correctly. Companies that solder usually have training and quality checking processes in place to ensure they know the condition of those joints.
Excessive wicking up the soldered wire, stiffening it and making it more likely to fail, has been mentioned. You can usually control that by untwisting the wire a bit so the joint has very tight twisting, and immediately away from the joint the individual strands don't touch each other tightly. The solder loves to run up between tightly packed strands, but if you loosen it a bit, it just won't go.
That is why I usually crimp then solder: The crimp provides a tight nest of tiny, solder-friendly gaps, and it keeps everything from moving.
But I also sometimes just crimp, when I've got confidence that the crimp is right. I own about 8 different crimpers, about 3 of them ratcheting.
I had to watch a training video on soldering and crimping probably 15 years ago. That video showed how crimp manufacturers and serious OEMs (such as VW, I'd guess) actually cut up the crimps and view the contact areas inside with scanning electron microscopes to verify that the metals were doing what they were supposed to do---it might have been diffusing, but I can't remember.
Anyway, seriously, I feel like I'm beating a dead horse. If you don't solder very well, practice. If your crimps are loose, make some practice crimps and pull them apart or cut them up (slowly) with a dremel tool and polish the cut so you can see the joint. Use a good magnifier or a microscope. And find some good heat shrink tubing (which also requires a few practice runs).
Properly done crimping is fine. Properly done soldering is fine.
The problem is: What defines "properly done"?
I guarantee you that VW not only specifies which crimper to use for each crimp, they actually verify the process doesn't wander by replacing dies on a schedule or periodically sending crimped components to a metallurgical lab.
Unless you use the tool recommended by the crimp vendor, and match it with the correct number and size of the conductors (that is, say, 2 wires of 14 gauge), then you really can't be sure.
Same thing with soldering. You need to be able to verify (usually visually) that the soldering is done correctly. Companies that solder usually have training and quality checking processes in place to ensure they know the condition of those joints.
Excessive wicking up the soldered wire, stiffening it and making it more likely to fail, has been mentioned. You can usually control that by untwisting the wire a bit so the joint has very tight twisting, and immediately away from the joint the individual strands don't touch each other tightly. The solder loves to run up between tightly packed strands, but if you loosen it a bit, it just won't go.
That is why I usually crimp then solder: The crimp provides a tight nest of tiny, solder-friendly gaps, and it keeps everything from moving.
But I also sometimes just crimp, when I've got confidence that the crimp is right. I own about 8 different crimpers, about 3 of them ratcheting.
I had to watch a training video on soldering and crimping probably 15 years ago. That video showed how crimp manufacturers and serious OEMs (such as VW, I'd guess) actually cut up the crimps and view the contact areas inside with scanning electron microscopes to verify that the metals were doing what they were supposed to do---it might have been diffusing, but I can't remember.
Anyway, seriously, I feel like I'm beating a dead horse. If you don't solder very well, practice. If your crimps are loose, make some practice crimps and pull them apart or cut them up (slowly) with a dremel tool and polish the cut so you can see the joint. Use a good magnifier or a microscope. And find some good heat shrink tubing (which also requires a few practice runs).