Thanks much.

It was pretty straightforward. Here's the steps that worked for me.

I placed the round table frame upside down on a piece of cardboard and traced an outline with a pencil. I then cut the cardboard, slightly undercutting the outline. This provided a cardboard template that was the same size as the inside of the frame.

I placed the composite deck boards face down and clamped them together temporarily with pipe clamps. I then traced an outline on the back side of the board using the cardboard circle. Once I had an outline, I marked the locations of the pocket holes. Outlining the circle before marking the pocket holes allowed me to make sure I wouldn't have any pocket holes / screws on the cut line.

I secured the bottom side of the boards with pocket holes using my Kreg jig. I used Tightbond III glue between the boards as I secured them together with pocket screws. I wiped off excess glue and let it dry overnight. I used a jigsaw to cut the table as outlined and then popped the new top into the circular frame / table legs. Although it fit perfectly, I added a bead of silicone along the bottom side at the edge of the table and frame.

Good luck with your project.

Thanks much. It was nice to make something functional again when my friend was about to throw it away.