MJ Sailingvideo
Six Layers of Fiberglass and Zero Regrets (MJ Sailing - Episode 372)
January 10, 2026 · 24 min · 47K views · Kent Island
Man guides 600lb engine into boat with crane
What this video covers
Matt lowers a 600-pound diesel engine into the engine bay of a catamaran under construction using a chain hoist rigged to an I-beam running fore and aft on deck.▶ 2:50 The engine is set temporarily on unglassed foam motor-mount pads while he checks shaft alignment with feeler gauges to confirm a consistent gap around the coupler.▶ 5:34 Once alignment is confirmed, he bonds the steel mount plates to the fiberglass substrate using a two-part methacrylate adhesive rated for metal-to-fiberglass bonding, then removes the engine entirely to glass the mounts in properly.▶ 15:38 Six layers of 12-ounce double-bias fiberglass secure the mounts, each layer stepped back 20 mm from the previous to distribute load across a wider area rather than concentrating stress at a single edge.▶ 20:22 Total Boat polyester fairing compound fills coves where mounts meet stringers before glassing.▶ 19:58 Separately, the owner's-hull media cabinet receives scuff sanding with 80-grit, fairing compound, three coats of Alexseal primer, and four coats of paint — a diesel heater with a directed hose keeps the cold workspace warm enough for proper cure.▶ 22:37 Six layers of stepped fiberglass over bonded mount plates is the chosen standard for a high-torque diesel installation in a load-critical engine bed.
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