Jon,

the ply that you saw is not marine ply. Ply that fits your description will also have joins in the face veneers and will probably not be all that good (and void-free) in the core veneer. They will probably have only one good face veneer, too. Are they marked A/C? This tells you something about the grading of the face veneers.

Despite this, if you select carefully, these plywoods are adequate for building kayaks. They should be a lot cheaper, too. Just be careful to select sheets with no voids (gaps or breaks in the face or core veneers) visible to the eye. Check carefully along the edges of the ply, to assess the quality of the core.

One eighth inch (3.2 mm) lauan door skins from BBC or Mitre 10, with careful selection, should do the trick. There are several kayaks in the NSW Sea Kayak Club made from door skins with 6 ounce glass. The results speak for themselves. There are also several kayaks built from 3 mm Hoop Pine or 3 or 4 mm gaboon marine ply. There is even one in (very heavy) 4 mm Fijian Kauri marine ply, which is in construction. This will be a rock-breaker. Kauri probably doesn't need glassing! Given the choice, gaboon is still the best all-round option amongst the marine plywoods.

Marine plywoods have equal-thickness veneers. That's part of the specification.

Not all gaboon marine ply really is marine ply to BS1088 (British) or AS2272 (Australian) standards. There are several countries that stamp BS1088 on plywood, even though it doesn't meet the specs. Chances are that these plywoods will be OK despite the deception.

Equal thickness veneers are useful, as they allow you to round your joints over a little more, without exposing the core veneer of the plywood. Same goes for using 4 mm instead of 3 mm. Rounder (larger radius) chines and sheer make it easier to wet the glass flat against the joint.

Note that, even in plywood from reputable sources, 3 mm marine ply will usually be over 3mm and heading for 3.5 mm.

Let us know how you get on. What are you intending to build? The Sqeedunk Cormorant 16, that you mentioned a little while ago, looks simple and neat. It should handle well, too. Multi-panelled decks look good on the Coho from Pygmy and the Merganser from Shearwater Boats. If you're adventurous, then you should try the Squeedunk multi-panelled version.

I can recommend Bote-Cote epoxy from Queensland. Their water-based (!!) air-curing polyurethane varnish/paint called Aqua-Cote is good, but test it first - we had a batch which required a vastly different ratio to what was on the label. They will deliver, or there are distributors on NSW, Vic and Tas. There are lots of local suppliers of glass and other bits. Try Big-W for gloves and brushes. Lincraft (!!!) have very cheap foam brushes - under a dollar each. They seem to be OK quality, too. You can save a lot of money by keeping the cost of consumables down. Mitre-10 has 20-gauge gal wire.

Good luck

Andrew

: Hi all
: Well after finding a design of kayak I like (Cormorant 16) I decided to go to
: the plywood shop to have a look at what type of plywood is available.
: They had some gaboon (okoume) but the 4mm plywood has 3 plys and the 2 outer
: plys are very thin (<1mm)and the inner ply was about 2mm. Is this
: normal as some of the other types of 4mm ply had 3 plys of equal
: thickness. This is a specialist plywood shop and I thought they would have
: the highest quality.
: Does gaboon ply come in different qualities, I think this stuff was made in
: France.
: TIA
: Jon