Originally Posted by sailboy21
Sorry MaineSail. I remember that thread but I keep getting mixed up by BoatLife's advertising. It is a good thing you actually spoke to them otherwise I might have taken their product descriptions too literally
I think both will cure but I'd be more comfortable with a product like 4200 Fast Cure than a slower curing polysulfide given the water and air temps and I generally don't like polyurethanes but I think this is one application that supports a fast cure product.
What I would do is get your boat ready for the tide cycle and tied in place on a dropping tide. At this point, and after plugging it from the outside, remove the gate valve. If you don't break the original seal on the thru-hull doing this yee hah! If it works you still have enough tide to bring her back to your slip and call it a day and if it does leak you're ready for the tide. Even if you break the seal of the thru-hull it will most likely be a drip, drip leak not a gushing river. So you can wait for the tide and be redy to go the minute it drops below the level of the through hull. Fly fishing waders work well to give you more working time. I used to careen my lobster boats when I was younger so I know the drill..