Pre-made rod grips are available, but I chose to buy cork rings. This fiberglass blank is .435 to .403 diameter in the span of the grip, and I thought it would be difficult to enlarge a 1/4 inch bore (6.5 inches long) with just a rat-tail file.
An HSS boring tool did a reasonably clean job of enlarging the initial holes in the cork rings. And, I could decrease the bore a little on each successive ring to follow the blank diameter.
It is a rather unusual tool that I show here. I am not certain that it was designed for boring, but it worked.
I tried the standard Sherline HSS tool also, and it was satisfactory.
Then came a nasty surprise. After I glued on the threaded part of the reel seat (5 minute epoxy, of course), I saw that the last thread was not fully formed, and that I could not screw on the locking ring.
At this point, everything is glued to the butt section of the blank. Here is an improvised setup for trimming off that last thread.
Reel seat complete, I could then glue on the cork rings.
The next day I made an outdoor setup for shaping the grip, using a wood rasp and then sandpaper.
And here is the finished grip.
I am not totally satisfied with my attempt to form a “Half Wells” style grip. This is a freehand operation, and practice would help.