: They might offer you some hoop pine ply, it's a lot lighter in color than the
: gaboon but it's less than quarter the price ($16 per sheet versus $83 per
: sheet). My first response was to say forget it, but now that I've seen
: Andrew Eddy's sheerwater baidarka (He's another Sydney-sider) that he made
: using the hoop pine, I'd give it a go. Very nice looking boat.

Yes, the boat looks wonderful - a pale straw yellow colour and an unusual shape. Big catch: there are some _severe_ and unresolved problems with the Hoop Pine. The problems arise from the Hoop Pine's softness and the very poor penetration of the epoxy into the surface of the ply.

I thought, all the way throught the building process, that I was getting good uptake of epoxy. The joints between panels showes excellent uptake especially along the grain - up to five millimetres penetration from the edge of the panel.

Unfortunately, my cross-sections (ie from the cockpit cut-out) show between 0.1 mm and 0.2 mm epoxy penetration depth into the outside layers of veneer. That's 20 to 40 thousands of an inch, for the metrically challenged. This is not enough to stop even small bumps or limited pressure on the surface of the deck, inside the cockpit or on the underside of the hull, from denting the timber and _delaminating_ the glass. The epoxy is hard and well cured, there are no problems with the glass, it's the epoxy _penetration_ which is the problem.

I have applied the epoxy as in the manufacturer's recommendations:
* over 20C - usually applying at over 23C and curing on a falling temperature
* using the supplied penetrating additive in the saturating coat
* sanding before the first coat
* correct mixture - even to the extent of calibrating the metering pumps
* blah, blah, blah

Hoop Pine has a very fine, close grain. Added to that, the veneering knife seems to burnish the veneer, but rough sanding with 80 grit seems to make no improvement. Moisture content was not a problem - samples of our sheets of plywood vary from 8.9% to 9.8% moisture content, which is well below the 18% maximum in the epoxy manufacturer's instructions.

The net effect is that I have squillions of small white cross-hatched dings in the baidarka, after only three test paddles. In two cases, just resting the paddle on deck, while getting in and out, has dinged the surface!

Go for Gaboon (Okoume). There's a good reason why everyone else uses it! If I get more information that seems to exonerate the Hoop Pine, I'll post it here.

Merante, Kauri, Vusa are all made in marine grade ply. These are nice timbers, but they are all denser than gaboon. Stick with the gaboon.

Andrew