Also, I sanded the fiberglass on the upper centering ring and and applied a coat of epoxy. The technique I use is to dam off the edges of the ring with masking tape, then pour epoxy into the ring. To get a smooth layer that spreads out smooth as glass, I use my heat gun to heat the epoxy. The heat causes the epoxy to flow as easily as water, creating a perfect, clear pool all the way to the edges.
Here is an example of the wet-out fiberglass on a centering ring. The green film and tape squeezes the fiberglass down against the tube, assuring a solid joining over the curves of the fillet and body tube.
