I agree with all that has been said, more or less.  The two key points for
me are:

1) Tinning the wire wicks solder up the stranded wire into the insulation
region and defeats the strain relief that wire insulation naturally gives.

2) Tinning the wire can also wick up nasty flux components that will
eventually eat the wire for lunch.

3) Crimping is dependent on the having the right cross-sectional area of
metals with the right modulus inside the crimp die.  The crimp dies were
designed for copper wire, phosphor bronze terminals, etc.  This does not
mean they won't work with tin/lead in addition to the other metals inside,
it just means that someone has to do a lot of homework to figure this out.
Any takers?

4) I cannot find my IPC Handbook on counting.  Someone please assist.  This
is beyond coffee, time to "do the Dew".


Next time a design engineer asks why you don't tin wire before crimping, the
best approach is to smile and simply say "Because".  Engineers understand
and readily accept this answer.  I particularly appreciate it when
manufacturing gives me this answer to a legitimate question.  It shows that
they've carefully thought through problem and they know I can't do anything
about it.  Did I tell you about the 200 pound Muskie I caught ice fishing
this year?

Regards,

Seth Goodman
Goodman Associates, LLC
tel 608.833.9933
fax 608.833.9966

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