Hi all - I am after an impartial sanity check. I was wondering if anyone has done testing for the actual stiffness achieved in your EG builds. I realise this may be rare for hobbyists, but perhaps you have made a coupon and rigged up something basic to estimate stiffness.

I ask in part because I have commissioned a test of a commercial solution - i.e., I paid for an expensive ready-to-go granite mix with correct epoxy dosing, had the coupons made by professionals, and had the coupons tested in a lab...I cannot be too specific about the manufacturer or numbers, but the tested Young's modulus was about 1/3 of that claimed.

Testing was flexural (4 point bend) - I wonder if larger numbers are in part a consequence of pure compressive testing.