When I haul out this spring for new bottom paint, I want to replace my thru hulls. I have two that I never use, one is a 1 1/2" that was used for direct discharge thru a Y valve from the head. The other is a 1" for salt water pump at galley sink.My question is does anyone make a "solid" thru hull "plug" that would fit in place of existing thru hull that could be removed if desired in the future? My thru hulls are the flat type that have a tapered hole in hull. I currently have caps on them, but they are still a concern and I don't want to fill them in as the next owner may want to have them reinstalled. TIAForrest