I have a solid vinyl fence that I want to put a hole in to use like a bigger peep hole. I plan to drill a 3-4" hole and need a grommet for the hole to keep anything from getting between the hollow section of the vinyl slat. I was think of using a desk grommet but dont think it will hold up to the weather and want something a little more secure, maybe something that has a flang on one side and is threaded on the other for a nut? Other idea is to glue in a piece of pcv pipe. Anyone know of anything that may work?