> It may be so flexible that it does NOT break at the clamp, too! I guess
> that would be technically a failure in the testing method, but what a
> paradox -- something that failed becuse it did not break.

With the beam method, the bending stresses start at zero at the point of loading, and increase linearly until the clamped end, where the forces should be the greatest. This is what we would expect for homogeneous materials, such as a steel beam, but variations in wood may cause failures at places other than at the clamped end. A kayak bounced off a rock will see the highest stresses at the point of contact, and this is better represented with the 3-point bending scheme. In this case, the bending stresses are the highest at the point of loading and decrease to zero at the supported edges.

> Considering the difference in price, if you are testing for
> greatest strength at lowest cost you may find that 1/4 inch lauan and
> polyester are a good combination. Or, you may not That's what the tests
> are for, right?

I was considering lauan, but most people build with mahogany, so I'd like to go with what would be most useful to most people. Plus, the mahogany will have fewer voids that could skew the tests. Cost-wise, I can get lots of test samples out of a single sheet, so I'd be willing to fork over the dough for a sheet of mahogany.

> hope these suggestions are of use.

> Paul G. Jacobson