It's got nothing to do with the coils inside the gun.
Heating the vice and subjecting it to a mechanical shock
removed the magnetism.
There was no heating of the metal. I re-read what I wrote
and that wasn't clear. What I meant to say was that although
the tip of the gun got hot, it wasn't used to heat the metal,
and that
that heating didn't play a part in the process.
So I agree that the mechanical shock was part of what
did the trick. Since heating wasn't involved, I have to
believe that the proximity of the coils inside the soldering
gun to the vise pads contributed to the final reduction of
the magnetism. It would make sense since the EMF was
changing as I moved the gun past the length of the metal
pads.
The field generated by the heating coils would be
minute because the wire is not coiled round a
ferromagnetic core which concentrates the flux.
IANA physics major, so I can't attest to the strength
of the fields outside the coils vs. at the center of its
windings, but since there's enough EMF to move the
shavings around on the surface of the vise, I have to
believe any effects from the EMF of the soldering
gun on the metal pads of the vise--even if it were
small--would still help the overall process.
Or, could I just have just omitted the soldering gun
and simply whacked the pads with the hammer and
accomplished the same thing?
Doug