Building the Wavelength 780

Construction

Will I be able to build a ‘Wavelength 780’

This is a feasible project for home building where most jobs can be managed easily by an individual builder in a larger sized carport or garage. Access to a larger shed is a bonus, however. Additional help will be needed from family/friends for moving completed hull sections out of moulds and into position for the join up of hull components, fitting the beams etc.

Builders are supported by:

  • A video of the early stages of the project, in particular building the floats,
  • A full CD of digital images (can be zoomed in) of all aspects of the building process,
  • Full size templates of most specially shaped parts of the boat, including annotations on reinforcing timber required and notes on fitting where appropriate.
  • Patterns and instructions for building the special moulds, e.g. the beam mould, are included.
  • A detailed building manual accompanies each stage of construction, e.g. ‘Building the floats,’  ‘Fitting the beam box frames in the main hull” etc.
  • Finally, designer support is available by phone or email if there are areas where further clarification is needed.

The skills required are those of an adaptable home handyman, including some familiarity with plywood and light timber, basic carpentry, woodworking and fibreglass skills, plus some familiarity with traditional wood/epoxy boatbuilding techniques.

(Recommended reading – the Gougeon Bros on Boat Construction)

Some of the particular construction features of the boat are:

  • Double thickness skin below the waterline and on the deck for stiffness and impact resistance
  • Single thickness curved skin underwing from above the waterline to the gunwale area on main hull contributes lightness and strength
  • Extra reinforcing in bow underwater impact areas on both the main hull and floats
  • Sacrificial foam/glass bows on the floats to absorb collision impacts.
  • A pivoting offset centreboard. While this system is not the choice of a racer, as it generates more drag than a centrally mounted daggerboard, its advantages for the cruiser are more than compensated for by the increased room and comfort in the cabin, plus its capacity to slip or release should the boat inadvertently touch bottom.
  • Fingertip control at speed with a balanced transom hung, adjustable daggerboard rudder. For the cruiser, this means minimum power use if auto pilot steering is fitted.
  • Strong internal lightweight keelson, coupled with and external skeg, to suit the cruiser that likes to “dry out” in suitable sheltered anchorages. A raised cabin sole, fitted on top of the keelson, ensures water from wet gear or sails does not pool on the floor of the cabin. Even with the raised cabin sole, there is still comfortable standing head room under the closed pop top, and headroom forward in the cabin for those of shorter stature, unusual in a tri of this length.
  • Sealed buoyancy spaces in the main hull, including forward beneath the anchor well, main cabin deck beams and sections of the forward box beam, void areas in the main cabin, ice box surrounds, rear cockpit coamings etc. The beams and floats are also independently sealed buoyancy units.
  • Safety provision for fitting a main hull re-entry hatch to Yachting Australia racing requirements, mid ships in the cabin if required.

 

How is ply used to create a modern, no compromise curvilinear style, rather than the flat, slab sided vessels usually associated with this material?

 The floats are built first in a single half particle board frame/batten mould and offer an easy introduction to the major aspects of the building process.

For each section of the boat, either half float, half hull or half deck, flexible, 4mm “A” Bond (marine glue bond) plywood is laid up dry in transverse strips approximately 180mm wide in a simple female particleboard / batten mould and temporarily held in place with  tech screws. The strips are quickly and easily trimmed with a hand held jack plane as they are progressively laid to keep all the planks at approximately 90 degrees to the main axis of the mould. A cordless drill plus button head tech screws quickly lock them in position.
Light cedar stringers are then glued in position longitudinally, side on, rather than the traditional edge on, to lock the ply strips in place. The stringers are bull nosed and coved with epoxy filler to allow a single layer of lightweight unidirectional glass to be laid up over the interior hull skin and fore and aft stringers in the one operation. Additional structural glass is fitted in stress areas. Internal framing and furniture, where specified, is assembled outside the mould with the aid of full size templates, and can then be glass taped in position to create a strong, rigid structure before removal of the half hull from the mould for external glassing, fairing and final assembly.

Beams
A smaller single particle board mould is used to make both the tops and bottoms of the “gull wing” shaped beams, which incorporate built in fairing. These are strongly engineered in multiple layers of structural unidirectional glass/ epoxy.

Space to Build
The minimum space required for the project would be a large carport of minimum dimensions 9.0 x 4.5 x 2.5m high, to ensure adequate room to build each of the major components on the building stock and then use the space to assemble the main hull. Additional space, or separate workshop area, would be required for fabricating frames, beams and supporting beam box frames, pop top, centreboard and cutting glass etc. This should be on a solid work table of at least the size of a sheet of chipboard (2240 x1200mm).  Useful power tools, such as a bench saw, sanding disc, drill press etc. will also require sufficient additional bench space to set up for efficient use.
If space is available, it is useful to set up the building strong back in a separate area from the space where the hulls will be joined and deck fitted. This will allow the job to proceed more quickly as work can be going on with join up of the main hulls while the deck components are still being fabricated.
Final painting and assembly will require more space outside, however this can be done under a temporary tarpaulin if necessary.

 Issues to address

 Some of the factors the builder will need to consider if building in a suburban area is contemplated, are:
Neighbours – Are they happy with a project that may take in excess of three years part time to complete?
Noise – Unfortunately, modern power tools such as circular saws and angle grinders create a noise hazard, both for the operator and for neighbours. Wear ear protection and avoid using noisy tools at night!
Dust – Where possible, use a workshop vacuum cleaner to clear dust from the project, as some individuals are sensitive to wood dust, and ‘cedar’ in particular.
Epoxy – This project uses epoxy resins suitable for use with timber/glass lamination. These have only a mild odour in the wet state and become odourless once cured, unlike polyester based resins, which exude strong styrene smells. Some individuals do develop epoxy allergies however, particularly if they are careless in handling the material over a long period without wearing gloves.
Paint fumes/overspray at the painting stage of project – This will obviously need consideration if neighbours are located close by, with temporary screening if necessary.

Tools

Power Tools:
These days, it is possible to buy a large range of cheaper power tools. As much of the project is working with thin ply and light cedar, in a ‘one off’ project,  these will suffice in most cases. Many of the shaping jobs can be done in different ways, including entirely by traditional hand tools. Acquiring a range of cheap power tools will speed up the process however. Buy them at the stage of the project when you consider they will be useful.
For those heavily used items, a better quality machine is recommended.
These include:
Jig saw plus different blade types as required
100mm angle grinder with flat pad sanding disc attachment – 1mm ‘Flexovit’ cut off wheels
Cordless drill with spare battery pack – long and short ‘Driver’ bits

Other items: (Many adequate cheap varieties available)
Bench saw (circular) with fine blade – adjustable height and angle
Bench mounted disc sanding pad
Bench mounted drill press – Drills up to 17mm plus base vice
Power drill – up to ½” bits – Bit sharpener attachment
Mitre saw
Power Plane (optional), standard wood plane, hand held jack plane
Orbital sander
Shop vacuum cleaner
Gas torch – (heat driver bit to remove epoxy embedded screws)
Compressor – spray gun (A good quality gun will be required if you are doing the final  2-pack polyurethane paint spray job)
Large range of cheap G, F and spring clamps.
Router – set up for bench mount if possible – Half round “bull nose” bits ¼”, 3/8” and ½” most used.
‘Workmate’ style clamping bench or similar – saw horses

Range of normal workshop hand tools:
Files, rasps, sanding blocks, levels, bevels, squares, Stanley knife,
Wood saw, hacksaw, chisels, screwdrivers, hammer,
Good quality industrial scissors for cutting fibreglass
Tape measure, metal rules, straight edges

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