Sealing thru-deck removable bolts

[s/v Jedi]

Originally Posted by Ryban

I think there are already wood blocks epoxied to the underside of the cockpit sole at these 4 locations as well as what looks like some white silicone or 4200 on top of that. It's probably a good opportunity to scrape all that off and start over. I have a suspicion that this sealant was cast in place over the threads, with perhaps some sort of lubricant on the threads, and thus acts as a seal when in good condition, at least for a few years.

I don't really like the seal-in-place solutions. On my last cruising sailboat, I was in my engine compartment all the time for either maintenance, to check the state of the stuffing box, and other various items. Probably at least once a month. On this boat, the batteries are also in this compartment, along with a few other items I'd want relatively easy access to.

In that case tapping thread and using rubber washers or O-rings will be the most convenient option. You can even think about hinges on one side and make it work like the hood of a car.

[guyrj33]

O ring, flat washer, spring.

[Island Time O25]

One of the boats I looked at a while ago had a 2" lip around the cockpit sole opening, then a hatch with latches all around, then a teak crate floor on top. At the time I thought of this set up as cumbersome but having snaked my way to the engine through the quarter berth or the lazarette too many times I would now gladly have this arrangement instead.

[Sailnav]

Plug the holes.
Use latches to hold down the lid.

[roverhi]

My W32 #163 had the cockpit sole/hatch sealed with what looked like LifeCaulk, definitely wasn't 5200 as I was able to pry the hatch off. Rebedded the sole and fasteners with LifeCaulk when I removed the hatch/sole for engine work. It didn't leak before or after wards Doing it today would probably use butyl as it would make removal easier.

People keep mentioning sillycone as a sealant. That's a really good choice if you want it to leak in the future and and be a total PITA to scrape the stuff off when you have to reseal it.