Your idea is basically sound, but: 1. Impact tests are very sensitive to support conditions, test piece size (and the phase of the moon)and simulating the real conditions is extremely difficult. You might get the material/construction combinations in the right order but their relative and absolute values would not be real. 2. Bending stiffness tests are really not necessary, you can calculate those. Laminating angle, layer order and actual thicknes cause so many variations that again the results are not very reliable in an absolute sense. Just by using a little more resin you can easily get bending stiffness variations of 30% which is quite enough to mask any other effect.
All things considered if you have the time and energy go ahead, you might get a few helpfull results but do not expect them to be very clear and decisive.

Tapio Manner

: OK, it's Science Fair Project time...........

: My son and I are interested in testing some of the common and maybe not so
: common materials used in kayak construction and comparing them. I would be
: interested in opinions on how to set up simple, repeatable tests that can
: be performed at home without expensive testing equipment.

: I would suggest two of the primary characteristics we are looking for in
: kayak construction material are rigidity and collision damage resistance,
: each in relation to weight. Rigidity is pretty simple. Collision damage is
: more complex, a function of a number of physicals (tensile strength,
: compresive, etc.) as well as structure design. I'd like to get past the
: physicals and onto tests that actually reflect the stresses put on our
: boats. I mean, when was the last time you pulled your boat apart end from
: end (i.e. in tension).

: I've seen a couple tests one can do at home: 1) Bend strips of materials over
: an edge with increasing amounts of weight on the unsupported end
: (cantilevered beam) until breakage. I think the Gougeon Brothers did
: something like this a while back. Seems like a good test of rigidity and
: how far a material will bend before it breaks and how it breaks.

: 2) Support a panel on its edges somehow and drop increasingly sized weights
: until failure to simulate running into a hard object like a rock.

: Any other ideas?