The test-bond of the two polyester/fiberglass tube sections is baking nicely on my dashboard now as a post-cure step. I faced my car into the sun, and the piece is too hot to hold, maybe 180F or so. To test it, I'm planning to use a 2x4 and my workbench, with a bathroom scale on one end of the 2x4, the tube bonding test on the other end, and a C-clamp that's about 90% of the way to the test article. That way the actual test force will be 9x the bathroom scale measurement. The bond line is about 3/4" wide, and the diameter is 2", so that's 4.7 square inches of bond area, all in shear. I think I'll stop at about 1000-1500 lbs or whatever makes me start being nervous about the 2x4 or workbench. I'll be surprised if it breaks before then, but that's what the test is for.