Construction Questions

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Q Can I use local timbers in place of the timbers specified in the design?
A Yes. Provided they meet certain requirements many timber species are suitable for wood-epoxy construction. The basic requirements are:

Dry. Timber needs to be dried (preferably kiln dried) to 12% moisture content or less. Air-dried timber seldom gets below 16% moisture content and this is too high.

Clean. Clean means reasonably straight-grained, free of shakes, knots and other serious blemishes. Small knots (say 10mm max diameter) are OK provider they are nice and tight, not loose.

Epoxy suitable. Timbers that contain a lot of resin (e.g. Pitchpine), tannin (e.g. Oak), or oil (e.g. Teak) are NOT suitable for structural purposes. They will not bond satisfactorily. Most softwoods and many hardwoods are suitable.

Note that Teak can be bonded reasonably satisfactorily provided the bonding surfaces are degreased well immediately
prior to bonding.

Not too heavy. Try to select timber with a density (at 12% moisture content) between 350 g/m^3 and 550 g/m^3 (22 lbs/ft^3 and 34 lbs/ft^3). Timber for deadwoods and keel can be heavier.

Here are some suitable timbers (in no particular order} which I have been asked about:

USA: White Pine, Yellow Pine, Cypress, Douglas Fir, Western Red Cedar, Northern White Cedar

Europe: Larch, European Fir, Norway Spruce, Russian Redwood

Australia: Paulownia

Most of these are suitable for most purposes, either as solid timber or as laminating timber. Very soft timbers, such as Cedar and soft Pines are not really suitable for hard wearing items, like keels and deadwoods, and not particularly suitable for laminated frames as the edges damage rather easily. Conversely Cedar is perfect for the strip planking inner skin of a cold-moulded hull.

There are plenty of other timber species around which are suitable. And remember that a species may go by several different names in different countries, or is maybe a related species. The timber industry truly is sales by confusion, with different species being called by the same common name and vice-versa. I will endeavour to make a list of timber species and their common names and add it to the "info" section of the website.

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