Chainplate leaks

[sparrowhawk1]

Okay thanks didn't realize it was in the link but I didn't check either.

[Celestialsailor]

Originally Posted by transmitterdan

5200 will always leak after a couple years. And it's a nightmare to remove. Sika or 4200 will also leak. Chain plates through the deck cannot be reliably sealed with non-gooey sealant.

Polyurethane sealants can work where they are under pressure but not in chain plates through the deck where the pressure can go negative. Butyl rubber will handle this case.

I rarely use 5200 and the few places I had to, never leaked after time. The same with 4200 and Silkaflex. So I don't know why it would leak for you after 2 years. I'm still thinking it's only condensation. When it hapened to me, I swore it was a leak. It would happen when I was inside my Olympian 34 with the heater on it during the winter. It would rain outside and I would have drips. Then I saw the ends of the 1/4-20 thru-bolt deck hardware doing the same. That's when I realized it was condensation.

[romanystar]

Thanks for all the thoughts.

The leaks are definitely salt water. I'm a full time cruiser, and the leaks only show up on passage. I don't think there is any flex between the decks and chainplates. I replaced the knees at the same time as the chainplates. They're real stout, and bonded to the hull and deck.

I can see how a caulk that stays gooey would work better than the goop I've tried so far. The flexible epoxy idea sounds interesting too.

Sounds like if I go with the tape I'll need to fill most of the gap between the deck and chainplates, the epoxy would seem to take care of that.

My big problem, now that I have some real options to try is to get materials shipped in to Rikitea, Gambier. My mate would like her clothing space dry before we do our next passage.

PS: To stick stuff to Starboard, first abrade, clean with acetone, flame rapidly with a torch. Straight talk from the manufacturer. I've worked for hours getting the 5200 to come free, this works.

[Terra Nova]

I admit I haven't yet tried fire.

Intuitively, one would think that the smaller the gap, the better, between chainplate and deck exit hole; less caulk. But the smaller the gap, the greater % of caulk stretching occurs from the relative movement between deck and chainplate.

[Nicholson58]

Originally Posted by sparrowhawk1

Use butyl rubber. It's also a good idea to build a raised section around the chain plate.

Probably the best choice. It will move and re-set like hot chewing gum.

[Nicholson58]

Originally Posted by Scottuk

Chainplates are polished to takes out scratches were water likely will sit and stay.

Polish is to help prevent anaerobic corrosion. It likes scratches & imperfections.