Waterproofing hull

[mrjd1981]

Bought a 1975 cat 22, the boat is great but there is a slow leak from an unknown source. I am going to attempt to go over the hull looking for any cracks and such and try to fill it with marine-tex......but I am wondering if anyone has any other suggestions on finding the source of the leak, or a sure fire way to seal anything that maybe open on the hull (sealing paint?)

[PaulinVictoria]

Is the water fresh or salt (assuming you aren't on a lake)? That will at least tell you whether the leak is above or below the waterline.

[hellosailor]

Odds are that it is not a crack, but a leak around a screw or bolt used to fasten something through the deck. Once you find it you'll usually need to uninstall whatever it is, dry out and seal the holes, and reinstall with proper gasketing or sealing.

[turbulicity]

It is unlikely that you have a crack in the fiberglass glass. Go through all the thru-hulls, close the seacocks. If you have an inboard, check the stuffing box. Check rudder bearing. If you have a water tank, empty it. If you still have leakage, get the boat out of the water as soon as you can and inspect the hull.

[mrjd1981]

we only noticed it after putting it in the water.. water was getting in from the keel lock down bolt, but that compartment is seperate from the other area of concern. The aft area of the boat takes on water very slowly. not a major concern because it is manageable and its taken out of the water after use. But would like to be able to seal it and enjoy a night or two on it.

Its freshwater btw.

[WDS123]

One technique ( After you have checket all the trough hulls ) is to lift boat out of water, many times one can see where water is leaking out of the boat.

That would be the leak.

[GaryHLucas]

I had a Catalina 22. The cockpit drains go to a through hull which is nothing more than a brass or bronze pipe nipple glassed into the hull. Try unscrewing the gate valve on that nipple and it often comes right out of the hull! That may be the source of your leak.

Gary H. Lucas

[TQA]

Get it dry and sprinkle talc around. This will show up the leak tracks if it it trickling down.