After the sealant set up, I carefully used the dremmel to cut the tube in half on both sides. I cut just deep enough to just get through tube wall, but not into the sealant. Once I cut both side it was easy to separate and ta-da, a perfect cylinder of fuel tank sealant. Now I just need to cut it to size and find a way to get it in place.
Note: this is not the final length of the cylinder bridge, but offered enough length so I don't have to add any more sealant to complete the bridge, other than stick it to the tray.
