Could someone please tell me what is the prefered material to fill the space between blank and slick butt on a stand up rod. Thank you, Larry

I use fiberglass dry wall tape and epoxy.

Spencer got It! about 4 rings. hold it on with a piece of masking tape roll it to fit. When you get al the rings done unroll them butter them with Kar-dol or other gel Epoxy as you roll them back on. Tie them off with a little thread and turn the butt back on

Barry and Spencer gave you the correct info.
Good Wraps Bob

Thanks Barry, Spencer and Bob. I used graphite arbors last time but they were pretty fragile after reaming inside. This will work a lot better.
Thanks again, Larry

The arbor will work just as well despite being very thin if it properly adhered to both blank and slick butt. The drywall tape is a good choice, one I use if the space to be filled is relatively small. If its a lot, the tape can add a bit of weight, but then if it's on a stand up ,or heavy rod, that won't really matter.