We have an 11C and re bedded all 6 chainplates last summer when we took down the mast, repainted it, all new rigging and lifelines. We took apart cabinets, I removed all of the burlap liner--am taking it off the entire boat--we cleaned them up and rebedded. We did not use butyl, used LifeSeal. (LifeSeal above the water line, LifeCaulk below the waterline, always.) Butyl tape is best used for anything that is trough-bolted. Our trim plates just screw into the deck, so LifeSeal is a better choice. We had a cosmetic crack in one of the chainplates, so we had a new one fabricated. I don't think they have ever been re bedded, and a couple of them had obvious long-term leaks, so the deck core around several of the chainplates was dust. We dug out at least 2" and then filled with epoxy. The great thing is these boats are built so well, they are very forgiving in repairs. We LOVE our S2.