Since the Moon's orbit centers on the Earth, rather than the Sun, it would be a little confusing to think of the Moon's orbit as a year. Instead, this cycle of the Moon orbiting the Earth is much closer to our calendar system of months. It takes 27.322 days (or 655.728 hours) for the Moon to orbit the Earth. If that number looks familiar, it's because the orbital period of the Moon is exactly the same as its rotational period.
A self-sealing stem bolt. Self-sealing stem bolts are a basic component of reverse-ratcheting routing planers. (DS9 episodes: Progress, Prophet Motive) They consist of 80% mixed duranium, aluminum, and steel alloys, 11% electrically modulated ceramic, and 9% thermally stabilized plastic.
Seal the transom core inside the bolt holes with epoxy resin. Use a syringe to inject the resin into the hole and a Q-tip or toothbrush to spread it around inside. Do this immediately before you insert the bolts. Seal and glue the board to the transom with 3M 5200 applied over the back of the board.