"jim rozen" wrote in message
...
In article , Lloyd E.
Sponenburgh
says...

They always taught us in electronics schools, "Make a secure
mechanical-wrap
before soldering; solder isn't glue."

Oddly this is actually incorrect. Yep, they taught the wrong
thing, but it is so widely accepted nobody ever questions the
mil-spec 'wrap three times before soldering' approach.

To convince yourself otherwise, make a simple lap joint using
stranded wire, with the lap being only two or three wire
diameters. Copper wire of course.

Then tension the joint until it fails by pulling on the wire
ends.

The joint does not come apart, even with standard 60/40 lead tin
solder.


Aw, Jim! I'm not parrotting some mantra I heard a few times. I was a pro
in electronics for decades until I retired, then started a new business.

A solder joint may start out stronger than the wire -- if you do some
'overlap' as you cite. (But that's not a compact joint.) But solder
strength deteriorates with age and mechanical and thermal cycling.

If you don't provide a mechanical joint before soldering you are
deliberately inviting a failure down the road. Since I've seen many
thousands of such failures, that's not speculation on my part.

LLoyd