Why Hemp Boats?

Extending Flatpack beyond the conventional plywood

Environmental Benefits of Hemp Boats

Created by potrace 1.15, written by Peter Selinger 2001-2017

Environmental impact

Hemp plants grow up to four times faster than other crops and is one of the most regenerative agriculture that requires fewer resources than many crops.

Created by potrace 1.15, written by Peter Selinger 2001-2017

Sustainability ​

Hemp takes in high amounts of carbon dioxide. For every ton of crop, 1.6 tons of carbon is removed from the atmosphere.

Created by potrace 1.15, written by Peter Selinger 2001-2017

Fabricator Friendly

Compared to materials such as fibreglass, hemp is safe to handle, cost-effective and easy to work with.

Hemp Fibre Resin

The Resin (ATL Composites  Kinetix R130 epoxy) is an eco-friendly alternative laminating resin, developed for surfboard manufacture, and well suited to boat hull lamination.

From ATL’s datasheet:

Components used in the manufacture of ECO-X R130 are made from renewable feedstock and by-product of existing industrial processes. Production consumes less energy and water than standard petroleum-based epoxies, and also reduces wastes and greenhouse gas emissions.

The Fibre (currently Margaret River Hemp Co 270 gsm Summer Fabric) is a garment-type fabric, well suited to this application.

The Fabrication Process supports high utilisation of the laminated material (minimal offcuts and wastage), and economical production runs of only a few boat instances. It is also kind to fabricators (itch-free grinding, and minimal fumes).

Sample Canoe Mould

Material (and fabrication process) Selection

Different materials, with their associated fabrication processes, are good for some market sectors, less effective for others. Comments here are representative; a long way short of a full analysis of merits and limitations. The importance of these factors will vary from instance to instance.

This has significant set-up costs, conventionally a plug, and a boat model set of moulds. Both material and fabrication costs are moderate. High strength, lightweight fabrications can be obtained, at a considerable cost premium, by using carbon fibre in epoxy, with or without vacuum bagging. Weathering resistance is high; wear and tear resistance subject to the laminates implemented.

These boats are formed inside a closed metal, with heat and rotation to fuse the polyethylene granules. This results in very modest costs for each individual boat supplied. Setup costs are high, with the requirement for an oven big enough for each mould, and relatively expensive heat resistant closed moulds. Weathering and impact resistance is high. Boats tend to be heavy, mainly due to the skin thickness required for local stiffness and puncture resistance.

The ubiquitous “tinnie”. Boats are light, with excellent durability.

Sheet is well suited to low-end trailable boats, at relatively high volumes, as pressing is required to generate panel stiffness. The plate is well suited to larger trailable boats and above, particularly at low volume. Boats can be built with modest facilities.

This offers a wide range of techniques, and opportunities for the application of craftsmanship, for individual boats and small production runs. Relatively lightweight construction can be achieved. Durability can be governed by paint systems, and enhanced by resin (with or without fibre) sheathing, at significant material and labour cost. Plywood stitch and glue constructions, often with pre-cut components, has widened the appeal and availability of timber construction for both the home and the professional builder.

This is considered in the current HFBWA  context of lightweight cartop or trailable flat-pack boats, and some specialised moulded boats. 

The combination of computer-aided design and CNC router cutting of components has given considerable flexibility to the application of this material.

Panel components can be laid up flat in lengths of up to 2400 nominal, and butted together to form strakes of the length of the boat. These components can be distributed in flat-pack form.

Each panel component is laid up against a smooth and flat mould surface, with shallow rebates at perimeter seams. This outer surface, when seams are completed, is essentially ready for painting, with a minimum of surface preparation.

Terminology

Common marine/boat building terminology is used throughout this website. However, some terms have specific meanings within the Hemp Fibre Boats contest.

Hemp Fibre Boats  – the entity behind bringing the Resin-Panel material into practicable boatbuilding. This website is part of the process. This is the brand for the project.

Mosman – house brand for designs developed within the Hemp Fibre Boats envelope.

Boat model – a specific design of boat, generally named. It may have variants. Think “car model” in this context.

Resin-Panel – a laminated material, with fibre laid up in a matrix of catalysed setting epoxy resin, against a surface mould (or a previous laminate).  It resembles glass reinforced plastics but uses hemp fibre in lieu of glass fibre. Laminates may be of single skin or sandwich construction.

Panel – a unit of Resin-Panel laminate, laid up flat, with its perimeter to the shape which, when joined to its neighbours, to forms the required boat shape. Length is normally limited to 2400 nominal, to suit CNC routers and flat-pack shipping.

Strake – a unit of 2 or more panels, joined end to end, and nominally to the length of the boat. End joints of panels will  be in Resin-Panel, against a flat backing surface.

Stitch and Glue – a technique developed primarily for plywood boat construction. It is a key feature supporting the building of Resin-Panel boats from flat pack components. Strakes are joined edge to edge initially  with cable ties. Some shaping may be enforced at this stage  to the relatively soft cable tied structure. Resin putty is fitted internally between the cable ties. Cable ties are then removed, the gaps and holes, both internally and externally are filled with renin putty, later sanded smooth. Internal and external surfaces are made good with strips of Resin-Panel, and then smoothed for painting. This process will be described and illustrated in project documentation.

*See the preceding photo of half length half scale CNC cut plywood model with cable ties.

 

The Mosman Canoe

River and ocean hemp resin fibre canoe. 17ft, 5.2 m with a single or double blade paddles. WA designed and made, with a capacity of 1 – 3 persons/paddlers.

The Herreshoff Swift Rowboat

This design will be offered in 2 length variants. The primary (17 ft) boat is intended for single person performance rowing (single sculls) and family use. The alternative length (14 ft) boat is offered for single person rowing (single sculls), and family use.

Get in touch

Contact Hemp Fibre Boats today for more information.

We welcome all enquiries, whether it is about a concept design, current design, implementation of an idea, or have a view of a concept design to bring to production!