Sealing Cabin Top Leaks

[dingfixer]

I recently purchased a 35' 75 Vindo to replace a Cheoy Lee totaled during Hurricane Florence.The cabin top is wood and has several small leaks that I can't seem to find. Anyone know of any product that can be used as a sealer for the entire cabin top ??

[Jahwork]

Hola,

I can’t answer your question about a sealer for the entire cabin top but I can share with you a technique I used with much success many many times way back when I used to work on boats for a living. We would take a large in line blower, similar to the ones you see utility crews using for ventilating underground vaults and other confined spaces, and put the elephant trunk, that is what they call the 8”, 10”, 12” diameter flexible accordion style hose, in through the companion way or a hatch and then seal around it with heavy plastic and lots of tape. Obviously we would close all the other ports and hatches and energize the blower, unless the pressure was too great and wanted to tear our fancy plastic/tape job, in which case we would adjust the pressure by slightly opening a port or two. Once the interior is pressurized we would then spray a mixture of dish soap and water over the areas in question, glass cleaner will also work well, and when you see bubbles you have magically found at least one of your leak points. Takes a little set up, and maybe renting the blower, but it never failed to find the leaks for us

Probably something you already knew but my wife tells me I am not good for much but pointing out the obvious.

Safe Journeys,
~Jake

[a64pilot]

What’s brilliant about the above method is you will find the ingress points of the leaks. If you try to stop the leaks from below you have found the egress points and the deck can still be leaking.

Now what’s scary is if you have soft spots in the deck.

[Orion Jim]

Brilliant solution. Never heard of this technique before.

[captmikem]

This works well, you can use the exhaust from a shop vac or a leaf blower in the cockpit or thru a port. I use Dollar Store detergent mixed well in a bucket then swabbed all over the house and deck, large bubbles or large groups of small bubbles form at the leaks. Have to remember to stuff the vents, anchor chain pipe etc.

M

[Shoalbay]

Love it. And it probably requires that I check my mast blocking, which is overdue anyway.

[Puget Dan]

Excellent process for finding leaks. Just like finding tire leaks. Thanks

[SVHarmonie]

I know they are hard to find, but find them you must. You can’t “seal them” without finding them.

If you have leaks in a plywood deck, the odds are that you have water damaged plywood you need to find.

[SaltyMetals]

You could try Capt Tolley penetrating fluid. V low surface tension so it finds the leak by capillary action and the seals it. look them up on the web. Absolute magic and so much easier than any other procedure.
Andrew
"Genial Bee"

[Mike Banks]

Fibreglass. Sand it back and epoxy saturate the timber using slow-cure epoxy thinned after thorough mixing with 20% by volume epoxy thinners. Keep doing this until no more epoxy is being absorbed. Then lightly sand, spread out your glass moderately heavy weave cloth, and get a roll of peel-ply cut oversize ready to hand.

Working from the centre of one edge, using un-thinned slow-cure resin (not if you are in low temperatures though--just if things are warm). Work that entire side, working your way backwards over the cloth adding resin with a roller. Consolidate if necessary using a consolidating roller.

When there are no more bubbles and the entire cabin top within reach is glassed, begin to spread your peel ply over it starting at one corner and working outwards and along one side, and broom it into contact with the surface using a soft floor sweeping broom, or a wallpaper brush if you can reach. Broom it smoothly and leave it level. .

This is not as easy as it sounds, but it does not matter if a few tiny ripples are left. They can be sanded out later. The peel ply is to give a paint-able surface and to keep insects from sticking in the epoxy. It is torn off and discarded after the resin has set properly.

While you are at it, it may also be a good idea to put guttering on the cabin top sides so as to harvest rain water should you ever need to remain in a remote place and your water-maker quits. My gutters were heavily made and doubled as a full weight hand-hold. They were screwed to the cabin top sides before the glass was applied, and the glass helped seal the gutters and terminated UNDER the gutters, the edges of the glass butted against the top of the cabin sides.

One thing I should mention though--is that if water has been leaking, it is almost certain that there will be rot. That has to be completely cut out and a plywood repair made and glued into place, before anything else happens.

[Hoodsail]

Jahwork, good idea. Remember reading similar method in Casey’s book, Sailboat hull & deck repair, except he used a leaf blower..He recommends running for 5 minutes to pressurize internally, but no boat size given. never tried it but maybe next Winter to track some annoying leaks..

[Tom in Florida]

I happen to be reading a book by Jim Trefethen. His solution is not so hi-tech. One person over the deck with a garden hose, slowly moving the stream from place to place. Add another person in the cabin with a flashlight. Sooner or later that person will see water coming through. Based on where the hose is shooting, that should identify the source of the leak.

[wguinon]

Once youve found and marked the leaks reverse the blower and suck the thinned epoxy into back into the leak

[a64pilot]

Originally Posted by Tom in Florida

I happen to be reading a book by Jim Trefethen. His solution is not so hi-tech. One person over the deck with a garden hose, slowly moving the stream from place to place. Add another person in the cabin with a flashlight. Sooner or later that person will see water coming through. Based on where the hose is shooting, that should identify the source of the leak.

The problem with that is that often water will leak into one place of the cabin top, travel sometime a long distance in the sandwich between the two layers and exit somewhere else.
Plus if you seal the leak from the bottom, the leak into the roof can still be occurring.

I manufactured an aircraft that had “wet wings” that meant that we sealed a section of the internal wing and sometimes we had leaks. We tested with air of course but some times a leak would occur still, often we had a hard time finding it, it would even seep in under a head of sealant in one place, travel several feet and then exit at times.

[Jahwork]

Hola once again,

I wholeheartedly concur with what A64 has said. It was not uncommon to locate multiple leak points on most boats I would test. Especially those with mechanically fastened decks, IE screwed down teak decks. It was also a common occurrence to find the water inside the boat presenting itself a great distance from the actual leak point, in some cases many feet. Water would frequently travel along wiring, plumbing, trim boards, etc before making itself noticeable inside the boat. I also used this technique to find the leak in my old motorhome a few years back and found the same situation, water was visible on opposite side of the RV from where the water was actually entering around the rooftop AC unit. With the myriad of stanchions, cleats, fairleads, toe rails, ports, hatches etc etc (you get the idea) on our boats there is no shortage of places for water to migrate in.

Happy leak hunting!

~Jake