BoatworksToday · video

What this video covers

Andy fabricates a custom fiberglass mold to create a watertight lip for the aft deck of a Bertram 25.15:03 The project aims to seal the transom area, preventing water ingress while accommodating future seating and storage.0:51 To achieve the necessary profile, he constructs a form and tests clear packing tape as a release agent against polyester resin, confirming it resists melting from the styrene.15:50 He chooses chopped strand mat (CSM) over 1708 biaxial fabric for its ability to conform to tight, intricate curves.16:31 He demonstrates a technique for tearing CSM rather than cutting it, which creates wispy, overlapping edges that lock together for better structural integration on complex shapes.18:59 He mixes eight-ounce batches of polyester laminating resin catalyzed at one percent with MEK, noting that the thickness of the three-to-five-layer layup will generate sufficient heat to ensure a proper cure.21:03 He also advises warming two-part epoxy cartridges like Thixo in a heating blanket to reduce viscosity and priming the nozzle before application to ensure a correct mix ratio.12:50

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