Quote:
Originally Posted by Rex Delay  It is a high density Neoprene bearing pad. Comes in varying thickness and would be perfect for both bearing and isolation pruposes. The size you need would probably be free scrap from any construction outfit that does bridges (large or small). |
Bridge bearing pads are generally meant to accommodate flat (horizontal) plate-to-plate connections, so a hollow vertical mast would require a closure plate (shim) on it’s bottom opening surface. Left hollow, the mast’s vertical edges would cut into the elastomeric isolator.