[Elecraft] Weller WTCPT tip life??

[Darwin, Keith]

Hi guys,
 
Work (ouch! I smashed my finger and it hurts to type letters like "ki,")
...... working on the KPA100 and have noticed soldering is tougher than
it was on the K2.  Heat transfer from the top to the part/board is hit &
miss.  When I clean and re-tin the tip of the iron I see it has a bit of
a golden hue and doesn't take solder well.  Switching back to the larger
(OEM) tip things get better.  I'm wondering if the tip or maybe the
sponge are just warn out and need to be replaced?
 
The Weller was new when I started the K2 and I used the small tip for
the K2.  Since then I've built a few mini-modules but not much else.
 
How long do these tips last?
 
- Keith N1AS -