Stella Hull Sheathing

Introduction

Hull sheathing has been permitted by the Stella Class Association to enable preservation and stabilisation of craft at more reasonable cost than major re-planking. It is not intended as a performance modification to gain a racing advantage by stiffening or improving the hull form and it is envisaged that the considerable weight of the materials used in the process would neutralise any such advantage.

Scope of Document

This is an advisory document and seeks to set out the best methodology for hull sheathing and make the owner aware of potential pitfalls in the process. It is not intended as set of “how to” instructions. The Stella Class Association cannot be held responsible for or assume any liability for damage to craft as either a direct or indirect result of any advice or information contained herein. Owners should be aware that the process will not rectify structural faults in the hull and cannot be regarded as a remedy for instability or a lack of soundness. Anything other than superficial faults must be addressed by a competent boat builder in an appropriate manner prior to sheathing.

Facilities and Competence

Those considering having their hull sheathed must be aware that it is a technically demanding process requiring considerable skill and experience in the use of epoxy materials and must be carried out in a temperature and humidity controlled environment. As such it should not be attempted by anyone other than a professional boat builder with the appropriate facilities.

Specification

Prior to commencement of the process the hull must be sound, stripped of all fittings and cleaned back to bare timber. It must be dried to a consistent moisture content of 15% or less throughout its entirety. Rubbing strake, rudder and iron ballast must be removed and a single continuous layer of bi-axial glass fibre cloth with a minimum weight of 450gsm applied from sheerline to sheerline including the transom using epoxy resin. It is imperative that absolute adhesion is achieved between the hull and the sheathing materials in all areas and that the sheath is absolutely continuous thus encapsulating the entire hull. Failure to achieve this will potentially allow water ingress between the sheath and the hull and set up future problems that would be extremely difficult to rectify.

Technical Advice and Milestone inspections

The Stella Class Association recommends that they are contacted by any owner considering sheathing so that the project can be discussed to ensure that a class-complaint outcome is achieved. The SCA also suggests that agreed milestone inspections by their technical representative are arranged to ensure that best practice is being observed throughout the process.