Drilling the Keel Bolts

While mounting the skeg, I also decided to tackle the keel bolts. The centerline of the boat had already been marked with a laser level and tape earlier in the build process. On the interior, I carried the centerline mark throughout and had already marked the locations for the keel bolts when installing the keel floors.

I began by drilling the holes from the inside out. To ensure the holes were straight, I attached a 90° straight edge to the keel floors using double-sided tape, which helped guide the drill. For alignment on the other axis, I relied on careful observation. Starting with a small-diameter drill bit, I checked where the hole emerged on the exterior. Fortunately, it aligned well with the intended position, being at most 1–2 mm off.

Gradually, I enlarged the holes, working up to a final diameter of 14 mm. The pilot holes I drilled from the inside allowed me to correct any minor misalignments on the exterior while still maintaining the correct position on the interior. This process required careful adjustments by eye and the use of a hand drill.

Preparing the Fiberglass Tubes

Next, I prepared the fiberglass tubes to line the holes. These tubes, with a 12 mm inner diameter and a 14 mm outer diameter, were sanded lightly on the outside and cut to equal lengths using a fine tool. Adding these tubes is essential for several reasons: class rules require regular checks of the keel bolts, and the tubes make removal easier while preventing any water ingress from seeping into the timber structure.

To install the tubes, I first taped off the holes on the inside and masked the top surface around the holes. Then, I filled the holes with epoxy resin, allowing it to sit briefly so air bubbles could rise and the surrounding wood could fully saturate. Once this was done, I inserted the fiberglass tubes, ensuring a solid, bubble-free bond around them.

Final Adjustments

After the epoxy cured, I cleaned up the area and drilled through the fiberglass tubes with a 12 mm drill bit. To ensure precise alignment later, I also fabricated a template to assist with drilling the keel itself. The accuracy achieved during this process gives me confidence that I could even have the keel CNC-cut with pre-drilled 12.5 mm holes. Time will tell how well it fits, but so far, I’m optimistic.