3 Years Of Building — And the Boat's Officially Closed In

Picking up right where the last episode left off — the roof panels are on the boat, roughly in place, and it's time to actually make this cabin top part of the structure. This is the episode where my 12.5 meter catamaran officially gets closed in. The panels went up rough. Now they have to be aligned properly, tacked in place with thickened epoxy, and then structurally tied into the boat with fiberglass tabbing on every seam. Once all the seams are done, the cabin top stops being a set of panels sitting on top of the boat and becomes one continuous, load-bearing structure. It's the last big exterior job on the whole build. In this episode, I go through the full process: 1. Aligning the panels 2. Filling the seams 3. Removing the straps 4. Tabbing the seams 5. Prep work 6. Sealing the inside Getting the alignment right is honestly the hardest part — small gaps and small misalignments now turn into hours of fairing and sanding later. Once everything is clamped and strapped where it needs to be, I pipe thickened epoxy into the gaps to lock the panels in place, let it cure, and then start the real structural work: laminating fiberglass strips over every seam, on both the outside and the inside. Working overhead is the least fun laminating job in boatbuilding, but we wet out the fiberglass flat on a table, roll it up, and unroll it directly onto the ceiling of the saloon. Way less mess, way less epoxy in the hair. Kyra also cut and rolled every peel ply strip we needed, which saved me a lot of time — the tabbing job would have taken twice as long solo. The payoff moment is standing inside the boat when the first seams are done and looking up at a continuous roof. For the first time, the saloon feels like a room. The cockpit has a covered space. There's a flat platform up top for what will eventually be around 2,000 watts of solar. It stops being a construction site and starts being a boat. I've been building this catamaran from scratch for the last three years, and this is one of those episodes where it really shows. Still plenty of composite work ahead — more tabbing on the inside, deck laminates, unidirectional reinforcements for the mast and shroud loads, and eventually all the fairing and painting. But closing in the boat is a huge psychological milestone. Thanks as always to everyone supporting the build, especially on Patreon — it genuinely helps keep this project moving, and honestly makes the difference between sneaking off to the boatyard on a weekend or not. The next episode picks up on the inside — starting to build out the interior structure now that the boat is finally sealed against the weather. If you want to follow the full journey of building a 12.5m catamaran from scratch, subscribe and come along for the ride. Links Patreon: www.patreon.com/c/BoatBuildingAndrew Instagram: www.instagram.com/boatbuildingandrew TikTok: www.tiktok.com/@boatbuildingandre #boatbuilding #catamaran #diyboat #composites #fiberglass #epoxy #sailinglife #boatyard #homebuilt #catamaranbuild #compositeconstruction #fiberglasstabbing