I just was reading through a ton of old interesting threads on chainplates, but didn't quite see what I was looking for. My new chainplates are going to be finished this week and the old ones have been cut down to be used as backing plates. My bulkheads are solid, dry and do not require anything beyond being cleaned up. The only sealer before I removed these plates was in the cabin top around the chainplate, nothing below that point.

What I would like to know are some best practices for installing and sealing the new plates up through the cabin top and the best material to use. I haven't been back up on deck to do more cleaning of the holes for the chainplates and do any isolation, but will do so on a good weather day. Torque values on the bolts, or just run them good and snug? What else do I want to know before putting this part of the puzzle back together?

Dave,

Read my blog here about the silicone skim coat I put on the chainplates and allowed to dry before installation. Torque them snug and you won't have any problem.

http://j30rhapsody348.blogspot.com/2012/12/new-chainplates.html

Bill,
What is your recommendation for the sealer material in the cabin top around the chainplate? Whatever had been used before had worked, but it had become brittle which seems like a bad thing.

Use something soft and pliable that expands and contracts with the changes. Boatlife LifeCaulk is good. Definitely not 4200 or 5200 or any Silicone based caulk.

For my chain plate re-install I first sealed the core around the deck cut out with penetrating epoxy and then installed the chain plates. Finally I used "Through the Roof" caulking from Ace Hardware to seal the deck cut outs. Thankfully my bulkhead was sound as was the deck around the cut outs.