Recently I got a new soldering iron from radioshack. I have used it on several projects and it has worked very well thus far. The last project I was working on, I noticed a small indentation on the end of the tip. I just got done desoldering some componets moments ago when I noticed the indentation has gotten bigger, looking like a cavity. I am sure most of you will already know exactly what I mean, but here is a couple pictures to illustrate what I am reffering to:
I know the pictures are a little fuzzy, though I took them using my iPod.
I am concerned about this tip and I am unaware as to why it has done this espeically since I have only had the iron itself for 4 days and have only used it for a few projects, using up maybe a foot of solder.
Could someone whom is more experienced with soldering irons please give me some info as to what causes this and why? and perhaps some info as to what should be done about it.
I am just going to replace the tip for now,

