: I am considering building a tandem s&g kayak for protected water touring and
: am a little concerned about the durability issue given the apparent
: lightness (4mm okume) of the wood portion of the composite material. Can
: anyone address this concern for me? Understand that I'm not looking for
: any guarantees, just some reasonable assurance that the boat will hold up
: under my normal use (20 heavy days per season). thanks

I was recently told by Dan(?) at Boat Craft out of Edmonton that stich and glue is stronger than cedar strip. His reasoning was there were muliple layers of wood all with uniform layers of glue between.

The jist was that this reduced the risk of facturing along a line due to a weak cedar strip, or glue joint.

He also pointed out that a multi chine hull would be stronger that a hard chined hull due to the panels being smaller. As well he mentioned that adding a layer of fiberglass on the inside increased the strength of wood by around 4times. with the deck on, fiberglassed both times that would increase to 16 times. This being an increase in strength over the ply wood alone with one layer of fiberglass on the out side of the hull.

His demo boats, which he lends out for test drives have the above layup, along with a layer of graphite/expoxy mix on the bottom for scuff protection. He says he has drug the kayak down the river has it scraped along the bottom for 20ft at a time. there were lots of scuffs on the bottom as evidence, but none seemd to go through the black layer. (He did mention the black layer was a bit of a trade off, it provided a hard and more sippery 'rub layer', which prevented the fiberglass from being worn. however a hard hit could damage the wood and you could not see it from the outside of the hull)

While I was in the store he actually climbed into one of the kayaks while it was suspended in two 'canoe horses' the center had no suport under it. It made me cringe as he climbed up and stood in the cock pit, but it it drove the point home that they are strong. I'd guess his weight at around 150lbs. this was a single kayak, not a double.

I've heard from several sources that a stich and glue is as strong as a fiberglass kayak.

I've not looked into any technical references on the subject, or done any 'engineering work' on it, but you wanted some encouraging words, and the image of him standing in the suspended portion of the kayak jumped out of my memory.

With the Black layer on the bottom, It seems to me it would be easy to build it up as it was worn away over the years.

have a good day.

Myrl