Originally Posted by
that dude who did that thing
First questoin is "does it need fixd?" Don't attempt to fix it unless the rod sections come apart under normal use conditions. But if it does you hvae some options.
First, generous application of candle wax might give you years of additional use before you have to do anything.
Second, on most rods, if you cut the female rod section back (I'd start with about a quarter inch), you can effectively reduce the taper size and create new gap. To do this you'd want to remomve the thread wraps over the and of the section. Use a fine tooth hack saw, and when you are done rewrap the end, and apply new finish. It's a lot of work, and it's not difficult, but it's picky stuff that needs to be done right.
Third, I have heard rumors that spin fishermen use some kind of spray that adds additional layers of carbon to the ferrule, effectively thickening it so it will fit more snugly.
Fourth, you could add a thin coat of epoxy to the ferrule to make it thicker. And then, if necessary, you could use very fine sandpaper (600+ ) to smooth the ferrule and make it fit. For a cheap rod, this is what I'd try. For an expensive one, you should consider taking it to a rodbuilder.