Fixing a leak from underneath.

Hi, I finally found one of the irritating leaks my boat has (1 more to find) but it’s kinda odd and I’m not sure how to beat address it. On the starboard side about midship and looking from underneath (I removed the teak in the closet to find it) there is a hole about were the stantions and teak rail are that has a green ground wire coming through it and no filler caulk/bedding, a slow water drip is coming from there. Being that I have no other Leaks coming in from the rails and the bedding on the bolts seems good would it be possible to inject something into the hole to seal it from underneath? If so what material would you recommend?
The green wire isn’t connected to anything so I could clip it and push it back into the hole.

Picture attached.

Thanks!

I'm not completely sure where the leak is but this stuff works well in a variety of applications.

Z-Spar Splash Zone A-788 Kit, Underwater Two-Part Epoxy Putty

Don’t do it.
The water is coming in from the outside, and that’s where it must be sealed.
If the fiberglass is cored in that spot, it is likely holding water between the laminates by now, and must be dried out before it is sealed up.
Railing post bases are notorious leakers, and are often installed incorrectly, so it might be a good idea to check the others too.

kapnd said:

don’t do it.
The water is coming in from the outside, and that’s where it must be sealed.
If the fiberglass is cored in that spot, it is likely holding water between the laminates by now, and must be dried out before it is sealed up.
Railing post bases are notorious leakers, and are often installed incorrectly, so it might be a good idea to check the others too.

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this>>>>>>> read it 10 times.

kapnd said:

Don’t do it.
The water is coming in from the outside, and that’s where it must be sealed.
If the fiberglass is cored in that spot, it is likely holding water between the laminates by now, and must be dried out before it is sealed up.
Railing post bases are notorious leakers, and are often installed incorrectly, so it might be a good idea to check the others too.

Click to expand...

Yes - Agree 100%

You'll probably find many more leaks at your stantion posts. It's just that not all are leaking through to the interior of the boat.

Yes, you do need to stop the water from the top, not the bottom. If you seal the bottom, it will just travel through the core and eventually come out somewhere else. You DO want it to come out the bottom asap when water gets in otherwise the water will just do more damage and you won’t be aware of it until it has done major damage. I never seal the bottom of any fitting that goes through the deck, just the top.

Understood, although in this area of the boat i fairly certain there is no core, I’ll confirm today. I’m hoping it’s maybe connected to the krogen name plate or something easier to remove and rebed.

According to the KK website:
"The hull and topsides of the Krogen 54′ were built of AIREX sandwich construction with deep layers of mat and glass roving. This construction remains one of the most enduring and safest afloat. (Closed-cell PVC foam core is absolutely impervious to water. No deterioration. No absorption.) The composite structure serves both as a buoyancy material and shock, sound and temperature insulator. It rides extremely quiet, greatly increases impact strength and eliminates condensation build up inside the hull.

Decks and superstructure were built of a DIVINYCELL sandwich construction. Foredeck and boat deck were molded with a non-skid surface. Aft deck and starboard side decks were built with a teak overlay."


So it sounds like the hull and topsides are have an impervious core, but the decks do not.
There are several different types of Divinycell. Maybe someone with more experience on it may want to comment.


btw - The KK54 is my vision of the perfect long range cruising boat. Treat her well.

Divinycell is just a different type of PVC foam core than Airex. Airex is more flexible and absorbs impacts better, Divinycell is stiffer and doesn’t ‘move’ as much with age or heat, thus better cosmetics. And it’s cheaper.
Neither will rot. But neither is there such a thing as a sandwich laminate that likes having water in it. Fix the leak from the top as best you can.

"The green wire isn’t connected to anything so I could clip it and push it back into the hole."
Green wires are usually bonding wires. If that wire is not connected, you might have something that should be bonded and now it is not. Or was there something that was bonded and is now removed?

Sealing from the bottom turns the wood, core, sandwich into a sponge. Enough water in the core or sandwich will eventually have water coming out somewhere else.
No boat builders I have seen in my lifetime, properly seal stanchion and other hardware screws. Bedding compound is great, but doesn't really seal the screw threads. As stanchions and other hardware gets worked, the screws will wiggle and allow passage of water down the threads. The only long term solution I have found is to epoxy the pilot hole when driving the screw.

Thanks for the push to fix it the right way everyone, It was a total pain but pulled off and re-bedded the railing and other hardware on that side. I think I found where at once maybe someone used that hole/wire. I did confirm on the KK54 that on the lip where the railings/teak is installed its not cored, at least it wasn't in the small areas I looked at. You are absolutely correct however that the top deck is cored as is the hull, from all of my core drills for new things including the stern thruster the hull thickness is about 3/4 fiberglass, 1/2-3/4 foam, and another 3/4 fiberglass maybe a tad thinner. Several areas were much thicker.

One leak to go!
AC

Good job Arthur.

You may want to rethink fixing that last leak. Better the leak you know....

I figure a boat will always have a leak. If you fix it, it just means the boat will spring a leak somewhere else, maybe a worse one.

Even should you decide you want to seal that hole the wire comes through do not do it yet.
Let it be a telltale that you have indeed stopped the leak. Leave it open for at least a few washdowns and rain storms. If no more water then think about sealing it.

Personally, leave it open.

I would purchase a new sharp drill bit of a common plug size , and try to drill up from the bottom.

If you drill thru to the outside a teak plug could be installed from the top.

If you go thru but hit metal I would stop drilling and insert a teak plug coated with epoxy from underneath.

This should stop the leak from top to bottom .

A small bit of alcohol , and a bit of extra hardener will have the epoxy chase any water that might be in the GRP laminate.

Or just use Git Rot on the plug .

Arthurc - last leak - I made a similar statement to a career shipwright then in his 80s. His response: "Fixed all your topside leaks, eh? You just haven't looked hard enough."

My experience has borne that out.

sbu22 said:

Arthurc - last leak - I made a similar statement to a career shipwright then in his 80s. His response: "Fixed all your topside leaks, eh? You just haven't looked hard enough."

My experience has borne that out.

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Yes, well aware of the joys of boat ownership, that said I have everything apart as she is being retrofit was was able to pretty completely check for any leaks, so im certain this is the last one. But with equal certainty I know something new will start leaking before the end of the rainy season here in the PACNW
AC