Your explanation makes sense. It brings to mind one additional question: Would plywood be more durable than wood strips due to it's alternating grain orientation? It would seem from the results of your tests that plywood should have a consistent strength in all directions of load, which might prevent some types of failures. Then again, is there any real data on the types of hull failures that are most common in kayaks? I would think that impact punctures are probably the most common and that this is where a cross laminated wood layup (like plywood) would be superior.

: I am not familiar with the tests cited in Kayakcraft. However, I doubt that
: the differences between their results and ours are due to test
: methodologies. In our tests, failure occurred in the tension side of all
: the specimens having the wood grain oriented along the long-axis of the
: specimen (parallel to the direction of principle stresses). When the wood
: grain was oriented perpendicular to the long-axis, failure occurred in the
: skin experiencing compression and in the wood core. Therefore, we had two
: classes of behavior, which reflected the two wood grain orientations.

: Load concentration can not explain the compression side failures because in
: most instances localized failure occurred away from the loading point. The
: simple explanation is that the wood core significantly contributes to the
: strength of the panel. In the case of wood grain perpendicular to the
: principle stresses, the wood core initiates failure, which leads to
: buckling of the skin in compression. Core failure and buckling of the skin
: in compression prevented failure in the tension side of the composite. All
: the tests were conducted in 3-point bending.