Walter,you know the benifets of spheres,but at 100% we do not know the vibra damping qualities.Shurly 3M with their high tec labs would do testing as it would benefit them if the qualities equaled E/Q or E/G in machine damping.Talking to a sales rep may prove interesting.
Spheres arrest cracking,besides other qualities and an E mail to 3M about our application may result in their labs testing for us.
Larry