I have a Weller soldering iron, with replaceable tips. It is more than thirty years old, I think, and I am more than thirty years older than I was when I bought it. Between us (Weller and I) we don't seem to be able to solder anything without the tip dragging a dag of solder with it as I remove the iron. Is there a simple, fixable, reason for this? I hope the answer is not merely a loss of dexterity on my part. New tips? New iron? If so, what sort of iron. It doesn't have to last another thirty years.