is there supposed to be a plug thing in the top of the butt section where it fits inside ferrule piece?

Sometimes yes, sometimes no-it depends on the design. I put a little 5 minute epoxy on the open male end; I figure it can't hurt to beef up the hoop strength a bit.

Yes. It helps to keep the end from splitting. The easiest thing to do is mix some rod bond and with your finger, Popsicle stick push it into the end. Then wipe off any that gets on the outside of the end.

Bill - willierods.com

Mark,
I just use a piece of solid graphite or fiberglass.
I cut a section a few inches long and chuck it into the end of a drill.
I start up the drill and hold it against a belt sander. When I get the piece to fit nicely into the end of the rod, I take out the piece and glue it into the end of the rod.
Then, I use an abrasive cut off wheel to trim off the excess piece of blank that had been chucked into the drill.

I use the large piece of blank material that I had chucked into the drill as a handle while gluing it into the blank. then the final trimming takes care of the issue, with no problems about getting any glue on the outside of the blank itself.

Take care
Roger

Wow, that's a nice suggestion. I'll have to use that one!

I've been getting rubber plugs at the hardware store and then epoxying them in place. Goodbye to that!

Whit