Way back when at GLLI...Dean told a group of us that the 14 to 100 parts by volume (weight) ratio was a result of real world experience. Since he started using URAC in that ratio, he had no handle pop-offs. Note that in his article "Thinking Glue", he says this produces the strongest bond. That doesn't mean that something close is not strong. He's had plenty of opportunity to see what works and what doesn't. We all learn as we go, but I trusted him on this one. It works, and I see no reason to change. Just my .02