Materials and substitutions

Plywood type:

50 years ago, decent marine fir plywood was available at a reasonable price.
Cheap plywood or exterior plywood as it is made today is not a good boat building material.
That plywood has too many voids and is often made from rot susceptible wood species. However, if you find a good batch of quality exterior plywood with no voids, you can use it if you entirely coat that plywood with epoxy resin.

Today, the best deal on marine plywood is Meranti BS6566.
Fir is still available but looks rough and should be reserved for interior parts like the framing, soles and inside layers of the transom.

Our recommendation: get Meranti or Okume for the hull shell and Meranti or Fir marine for the framing. To learn more about plywood selection, visit this technical support web site: link to bateau2.

Long plywood panels:

Many of the free plans specify the use of long plywood panels: 10', 15' long or more.
Those plywood panels are not available anymore and even if they were, it would be extremely costly to ship them.
If one wants long panels, they can be made by scarfing two shorter panels together.

Scarfing requires a special jig and some skills. It is easy to make a bad scarf that will break or be a weak point. We do not recommend a scarf unless you are familiar with the technique.

At Bateau.com, to produce long panels, we use different techniques proven on thousands of boats.

The easiest technique is the butt block: two panels are joined at their edges and a strip of plywood (between 6 and 10"wide) is epoxy glued over the seam.

This butt block joint is very strong, stronger than the plywood itself. However, it creates a flat spot when bending the plywood and we recommend it only in areas of minimum curvature. Also, the butt block may interfere with the interior framing.

A second and better method is the fiberglass splice. It is somewhat similar to the butt block: two panels are joined at their edges and covered on each face with fiberglass tape in epoxy.

The number of layers of glass varies in function of the plywood thickness,

The third and best method is the use of a puzzle joint.

Two sheets of plywood are cut like a puzzle along their edges, assembled with epoxy and covered by one layer of fiberglass tape in epoxy. This is very strong and does not produce a "bump" over the plywood surface.
The plywood store at BoatBuilderCentral.com sells marine plywood sheets with a puzzle joint along one or two edges.
All those techniques are documented at Bateau2.com and BoatBuilderCentral.com in the Help sections.

Marine fasteners and marine glues:

The free plans specify tight wood assemblies, screws or boat nails and marine wood glue. We prefer to use epoxy.
Epoxy can be used wherever the plans specify glue and fasteners.
Epoxy glue is gap filling and does not require precision wood work, it is forgiving to the first time boat builder and also much stronger than wood glues.
The epoxy glue sold at BoatBuilderCentral.com is less expensive than boat building wood glues.
Epoxy assemblies do not require fasteners: an epoxy assembly is stronger than anything assembled with screws.
You may use cheap drywall screws to hold parts together during the gluing but remove them after the epoxy cure. Try to break something assembled with epoxy and it is the wood that will split but not the epoxy glue.

Timber, framing wood:

All the free plans use hardwood framing.
That framing uses expensive and difficult to find woods like oak, cypress or mahogany. The parts must be beveled at the correct angles. This requires special woodworking tools and skills.
Instead of wood framing, we prefer to use plywood and fiberglass framing.
Fiberglass framing is simply a sufficient number of fiberglass tape layers where the plans show a solid wood member. It is easier to build, will never rot and is stronger. Think of it: the Cigarette racing boats are framed with fiberglass and they run through rough seas at 100 mph!
If you have the skills, tools and the wood to make your framing as in the plans, feel free to build that way but otherwise, consider our method.

Wood working skills and tools:

The free plans show wood assemblies that must be beveled and joints with tight tolerances. Some parts are caulked with putty, butyl tape or even cotton.
You can build a better and stronger boat without bevels, expensive tools and difficult to find materials by replacing all the above with epoxy seams.
See the section about building a better boat for details.