when to replace iron tip?

[hotshot9911]

Hey guys I have been soldering for a little bit now, but a question I haven't really asked and should help out some other beginners is when should I replace the tip on my soldering iron?I am using a Weller wcl100 and one of the chiseled tips that has the iron plated tip,but I have noticed were the iron plating has dissolved?flaked?off the end a little bit and was wondering when is the time to replace the tip while working on an amp??

[OnTheFritz]

Not to sound simplistic, but if you're not *soldering along* like you did when it was new, get a new tip. Will save you headaches.
Inexpensive and they do go south. I use a Rat Shack 30 watt iron, and the conical tip (I like) that keeps me using this, lasts one build with tweaks, perhaps a bit more like soldering buss wires etc.