I second the sealing with butyl. Do NOT use silicone or 4200. The epoxy idea may be ok, but messy and no going back. "Beefing up" the plates wont do any harm but isn't necessary. These plates effectively protect the sealant. That's it. Check the balsa core around the penetration. Depending on extent of decay, determine how this will be remedied -- from digging out a small amount balsa and fill with butyl to cutting out glass from above or below to repair and anything in between. Overfill with butyl fron above and below, then gradually tighten the cover plates to compress butyl and force it into all voids. Carefully trim all excess butyl that oozes out from under the plates and remove. Check frequently for leaks and gradual oozing of butyl.
The chain plates move in and out, perpendicular to the deck under load, unload. The sealing material must be able to move also. Epoxy will not move. Silicone will for a while, but it's difficult stuff to remove later if it fails. Same with 4200 but even worse. Butyl is the solution. Also, I encourage you to carefully inspect the knee connection where chain plate bolts to hull. Remove bolts and poke around with dental tools. Make sure plywood is intact and not rotting. Inspect in the bottom of the space below knee, poking and tapping everything, checking for hollow sounds and decay. If there have been leaks at the deck, water runs down chain plate and into all the plywood knee structure and can damage it. So, there is more to preventing water at the deck core. Much more. I am sure others on the list have stories to tell. A lister has an 81 C&C36 that is in for a major major repair (thousands $$) of the knees due to a leak. The rig nearly came down while racing. I was crew. Scary. So I immediately checked my C&C34. Leaking but very little decay. Dry as bone after butyl and 4 months -- haven't been to boat since about November, but under winter cover. Jeff Laman 81 C&C34 Harmony Ludington Mich Get Outlook for Android<https://aka.ms/AAb9ysg> ________________________________ From: MICHAEL BRANNON via CnC-List <cnc-list@cnc-list.com> Sent: Monday, March 21, 2022 5:38:59 PM To: Stus-List <cnc-list@cnc-list.com> Cc: MICHAEL BRANNON <ff1...@aol.com> Subject: Stus-List Re: Chainplate Sealing. John, I’ve owned my 36-1 since 1997. I’ve yet to make the chainplates quit leaking but I’ve certainly reduced the amount. First, I doubt that the balsa around your chainplates is sealed. Mine wasn’t. I had to replace core material on the starboard side. Second. Those aluminum trim pieces are flush to the deck. I raised mine about 3?16” and that is what made the difference. Lastly, Like everything else above the waterline I used butyl as the sealant. It remains flexible and easy to remove. My advise is to ask the butyl from both sides of the deck. Install the trim plates and see if it is sealed? Cheer, and best of luck. Mike Mike Brannon Virginia Lee 93295 1978 C&C 36 CB Virginia Beach, VA PS, mine need to be done again this year. On Mar 21, 2022, at 5:28 PM, Marek Dziedzic via CnC-List <cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> wrote: John, Many would suggest 3M 4200, but silicone has issues. I swear by butyl tape (it never hardens out completely and it is very flexible). The best source is Maine Sail (Compass Marine https://marinehowto.com/<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmarinehowto.com%2F&data=04%7C01%7C%7Ccb4a36365894410f988c08da0b8354c1%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637834955941777818%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=D%2FsSTOSoM9PpuLLRcc3qaZkNgrXXIzXYu0hYQVIVSvk%3D&reserved=0>), though, I am not sure if he still sells this stuff (he had a bad hard attack last year). Marek Ottawa, ON From: John McCrea via CnC-List <cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> Sent: Monday, March 21, 2022 4:28 PM To: 'Stus-List' <cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> Cc: johnmcc...@comcast.net<mailto:johnmcc...@comcast.net> Subject: Stus-List Chainplate Sealing. Hello. I have a leak on my port side chainplate that needs addressing. I pulled both chainplate cover plates and noticed that I had a stainless rod on starboard that holds the two chainplates pieces together. One on port is missing. Maybe that is causing excess movement and more adapt to leak? The covers are original and thin 1/16 aluminum. I am getting them beefed up to 1/8 stainless. Looks like the PO had only sealed them with clear silicone. So that will all be dug out. I am also inspecting the hull tabbing below with the chainplates etc to ensure that I do not have any issues there. What is the best sealant to use when installing the new cover plates? Thanks! Regards, John McCrea Talisman 1979 36-1 Mystic, CT
