Best caulk for deadlight?

Jan 24, 2018
17
Catalina 25 Whiskeytown Lake
I have a tiny bit of moisture inside the foredeck deadlight and want to recaulk the edges. Any recommendation? I know it’s best to avoid silicone. I don’t think I need to fully rip it out and rebed but just run a small bead along the edges. Thanks!
 

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Sep 24, 2018
1,475
O'Day 25 Chicago
Since butyl has low adhesion, it wont work if you just want to seal the edge. I've found that if it's exposed it'll often make a mess and get tracked elsewhere. I've read that 3M 5200/4200/4000 technically isn't compatible with lexan. 4200 and 5200 aren't the best for applications that are exposed to UV. Dow Corning 795 or similar is widely used to rebed windows and is what I would use in this application
 
Jan 24, 2018
17
Catalina 25 Whiskeytown Lake
Since butyl has low adhesion, it wont work if you just want to seal the edge. I've found that if it's exposed it'll often make a mess and get tracked elsewhere. I've read that 3M 5200/4200/4000 technically isn't compatible with lexan. 4200 and 5200 aren't the best for applications that are exposed to UV. Dow Corning 795 or similar is widely used to rebed windows and is what I would use in this application
Thanks! I’ve also thought about LifeSeal. Heard good things about it.
 

DArcy

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Feb 11, 2017
1,249
Islander Freeport 36 Ottawa
I have used Sikaflex 295 for bonding in acrylic windows in my previous boat. They are still looking good after about 10 years. I'd remove it and re-seal the entire thing though rather than try to lay a bead down around it.
 
Sep 24, 2018
1,475
O'Day 25 Chicago
I'm not sure about LifeSeal but I know the Dow & Corning and Sikaflex sealants mentioned in this thread are commonly used for this application. Removing and resealing like DArcy mentioned isn't as hard as you might think