Considering Fiber-Reinforced Composites for Sheathing

For their Narai Mk IV catamaran build, the author delves into the pros and cons of flax, hemp and basalt fiber composites for sheathing, as well as the benefits and difficulties of hand lay-up, VARTM and resin infusion techniques.

Angie Richard

March 17, 2025

Greenboats laying flax fabric to construct the MB9 monohull, which is entirely constructed from Natural Fibre Composites (NFCs). Photo courtesy of Greenboats.

As we explore material legacies and evolution with a regenerative lens for our Wharram Narai Mk IV build, the focus now shifts to sheathing techniques and materials that provide strength, water resistance and longevity. Historically, boatbuilders used natural materials like tar, animal hides and plant fibers to protect and reinforce wooden vessels. Today, there’s an urgency for boat builders to explore natural fiber composites as alternatives to plastic-based sheathing materials like nylon and glass-reinforced plastic (GRP), which negatively impact marine environments.