On Sat, 16 Sep 2017 17:03:05 +0100, N_Cook wrote:

snip

If we're talking magnastats here,

I think we are (if that's what the Weller Curie Point temperature
switch system is called). [1]

never throw away a bit without
removing the magnastat, quite easy to swage-fit to another bit of right
form but wrong temp.

Ah, and that explains the 'waisting' I saw on my existing (and only)
tip. Good tip. ;-)

Cheers, T i m

[1] Just looking up Curie Point science again it explains what was
happening the other day. When the iron was cold and the permanent
magnetic field was high in the tip it held itself into the element
(the end of the barrel was worn oversize and didn't retain the tip)
until it warmed up and then would fall out, just as it was up to
temperature. ;-)