I drilled out the area, taped the bottom, put the pvc sections in place, and poured thickened epoxy around them. I was also replacing the pedestal guard feet which required drilling some new holes, and filling old ones. I didn't seal the inside the pvc tubes, but they aren't getting any water in them. (I have rubber gaskets where the wires enter the guard rail at the top).Thanks Davester. How did you secure and/or seal the PVC?