The boat had a huge number of through-hulls in a variety of conditions. Five of these were not actually needed. These were removed. The hull was ground down with 1:15 ratio bevels around the holes inside and outside.

New glass and polyester layers were added on both sides, joining in the hole. Finally the outside was faired and sanded, and coated with tree layers of clear epoxy.

Then followed 4 layers of epoxy primer, and anti fouling paint for those holes that were below the waterline, while ordinary hull paint was applied above.

In addition to the removed through-hulls, I also closed the holes of the deck draining system. This system consisted of a grilled hole on deck and a vertical GRP channel following the inside of the hull down to exit holes below the water line. I figured removing a couple of additional holes in the hull would not require much more work, and would even further increase hull integrity. I confess I might have been carried away a bit; this was not really absolutely necessary... For those of a similar disposition, I should mention that the job involved removing the bottom of the internal drainage channels to get a good seat for the internal layers of glass fibre. These are quite big chunks of GRP, which is located inside quite small cupboards. Cut as much as possible, grind as little as possible, and wear a good mask and cover-all!

The remaining through-hulls were all removed and replaced by marelon (no corrosion, ever) throughhulls from Forespar. The exception was the cockpit drainage through-hulls that were larger than any marelon through-hulls I could find. For those I bought very expensive Danish high grade bronze through-hulls, which should last two or three decades at least.