: does anyone have an idea of optimum size, eg 1 cup, 2 cups, more?

Small end pours small will help keep the weight down.

Everyone seems to have their own way of doing it, and I'm certainly no expert, but I like to pour part of small end pours before joining the deck and hull so that handle holes can be exactly positioned. My end pours are made from a slurry of epoxy mixed with microballoons and wood dust.

The need for large end pours is reduced if the inside seam tape is almost all the way to the tips. To get the tape further into the ends, strips of fiberglass tape can be glued to the inside wall of the hull with hot melt glue before joining to the deck. When the hull and deck are joined, the tape in the ends is wet out with epoxy (brush attached to a stick). Learned the pre-taping thing on this message board and it works great.

After the hull and deck are joined with tape, I do tiny -maybe 2 ounce - end pours with the boat on end, to help join the deck to the hull and to seal the inside tips.

John C