PU Resin for Layer Damping?

[JAZZCNC]

I wish to make a layer damped gantry for a 3D printer. It will have two aluminium box section tubes (25mm and 20mm) placed inside each other and the gap between filled with a damping material.

PU resin comes to mind but I wonder what type has the highest damping factor? Or is something else better?

Thanks

I don't think you will get better than PU resin for dampening without going to heavier materials which will bump up the mass which you don't want for moving gantry. But if it's fixed gantry then filling it with concrete will be your best option as it's about the highest up the Stiffness/density chart without getting silly about it.

See this Young's Modulus- Density chart it graphs which material gives what performance comparing Stiffness to Density. PU is right about in the Middle.