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Building The Fiberglass Mold For The Aft Deck Cover #Bertram25

July 20, 2025 · 26 min · 10K views

What this video covers

Andy constructs a makeshift mold to cast a fiberglass aft deck cover for a Bertram 25.0:30 The project requires a rigid frame that accounts for the deck's five-foot width and three-foot depth.2:27 To ensure the final lid fits with approximately one-quarter inch of clearance on all sides, Andy installs half-inch spacers around the perimeter of the existing deck opening.1:00 He secures a frame around these spacers to establish the outer dimensions of the mold.1:21 After shimming the corners to maintain stability, he attaches a flat sheet of OSB to serve as the base for the casting surface.17:44 This approach aims to create a stable, non-binding lid that avoids the need for a central support structure across the wide span.2:27 The process involves precise cutting and fitting to ensure the mold remains square and properly oriented before the fiberglass layup begins.

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