BoatworksToday · video

What this video covers

Andy constructs a rigid, lightweight fiberglass storage lid for the aft deck of a Bertram by coring a pre-glassed panel with Kusa. The project aims to span a 3-by-5-foot compartment while minimizing flex.1:30 After sanding the initial three layers of 1708 fiberglass, he evaluates three coring options: 3/4-inch balsa, 1/2-inch Kusa, and 1-inch Kusa.3:15 He selects 1/2-inch Kusa to maintain a manageable thickness, centering the material to leave a 4-inch perimeter for glass adhesion.8:29 He bonds the core using 5-to-1 epoxy, chosen for its superior stiffness, and applies weight to ensure a thin, consistent bond line without squeezing out excess resin.9:49 He then applies a layer of 1708 fiberglass, noting that the finished panel exhibits zero flex but weighs approximately 70 pounds.25:48 The process confirms that Kusa panels require no surface sanding before bonding because they are factory-sanded to a uniform thickness.14:15

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