So, a few days ago I was trying to do some soldering and I found my iron tip just not cutting it. After taking off the tip its self, I have notice that an inner sheath hanging loose and easily removable. This is sitting between the heating element and the tip itself.
I did notice that the iron works fine with another tip. And I was always thinking it a tip had to be in real bad shape, before it needs replacement.
By the way, I have a Hakko FX888D soldering station.