Living For Sailvideo

The BEST Fiberglass Deck Core Materials (And How To Choose)

September 4, 2023 · 31 min · 68K views

What this video covers

Jon, restoring a Liberty 458 with a saturated teak deck screwed from the top, evaluates eight fiberglass sandwich core materials across nine mechanical properties to determine the best replacement for failed balsa and plywood cores.0:10 The nine criteria are shear strength, compression strength, shear-strength-to-weight ratio, density, water resistance, insulation value, workability, cost, and availability.3:08 Plywood (BS-1088 or BS-6566 marine grade) scores highest on workability and familiarity but rates poorly on water resistance and insulation (R1 per inch), with water migrating freely along its cross-oriented cells.9:40 End-grain balsa, at 6–9 lb/cu ft and roughly $7.50/sq ft, offers nearly twice plywood's shear strength and the second-best shear-to-weight ratio, but absorbs 600% of its weight in water at full saturation and is susceptible to rot.13:07 G10 compressed fiberglass-epoxy panel delivers the highest shear and compression numbers by a large margin at 112 lb/cu ft, resists water completely, and can be drilled and tapped to hold machine threads, but its weight makes full-deck use impractical, it dulls tools quickly, and its rigidity requires relief cuts on curved panels.15:24 Cost ranges from roughly $2 to over $100 per square foot across all eight materials; none are available at big-box hardware stores.6:42

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Boats in this video

Liberty 458Their boat

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