Hi Mike,
Looking at the picture of Paul casting again, the load that the Barrio rod is under is similar to the load I put on blanks in a maximum deflection destruction test that I do now and again. A sample of many of the blank models I have made has been tested to destruction using that test at some point.
The test is made by anchoring the blank by the butt horizontally in a specially made clamp, a weight is added to the tip, which is increased incrementally till the load causes it to break. It takes a surprising amount of weight to break even the lightest light line blanks.
Every blank built also gets what I call the "welly test." where the each section of the blank is bent to an extreme degree that will very rapidly show any anomalies in the blank construction. The blank is then assembled and given the same test.
Having passed that test, the rod blank can then be confidently built into the finished fly rod.
Great videos Mike H!
Regards,
David.