Finding Deck Leaks

[Schoonerman]

This has probably been covered ad nauseum, but I haven't found any archive references to it. I have a teak deck over plywood, roughly 40 years old. Well caulked, very little cracks or checking, yet I get lots of rainwater down below, seeming to come in around the four cabin corners where they meet the deck, as well as elsewhere yet undiscovered. I have gone over all with the proverbial fine-toothed comb, but cannot find where the heck the water is coming in. Any thoughts on how to track this down and solve the problem? Thanks.

[imported_Dutch]

How about usin a hose?

[ 09-29-2002, 08:17 PM: Message edited by: dirtyoldmanofthesea ]

[Kevin G]

From Don Casey's book:

Close the boat up and leave the companionway open. seal up the companionway with a plastic cover,(some sheet plastic), tape it as tightly as possible. Cut a slit in the plastic and insert the exhaust hose from a shop vac. Use a BIG vac if possible. Pressurize the boat for about 5 minutes, and then put soapy water around the areas that you think are leaking. The bubbles should show up where the water is entering.

Kevin

[Schoonerman]

Originally posted by dirtyoldmanofthesea:
How about usin a hose?Thank you both for responding. The obvious problem with using a hose, is the same problem any homeowner recognizes: If your roof leaks, where the water drips is rarely related to where it is entering the house. Same with a boat deck. Where it is dripping inside is most likely not the same place that it is entering through the deck. Kevin's suggestion is an interesting one that I will see if I can apply.
Again, thanks for the responses.

[Paul Scheuer]

Thinking out of the box for a minute - How 'bout selective placement of various colored tracer dyes or dyed water on the deck ? (easy for me to say)

[skuthorp]

How about coloured smoke? Not a flare as they make a mess. Strip the cabin of everything possible and chose a sweet smelling smoke source (sandalwood and honey?) They use smoke to find leaks in sewage systems here. I like the idea of pressurising the cabin and using soap best , even if it takes a few goes.

[Scott Rosen]

Finding deck leaks ain't rocket science.

A teak on ply deck can only leak at the plywood joints. There are really no other possibilities. If you're getting leaks around the cabin corners, then I'll bet that the leaks are from the joints between the deck and the cabin. The seam at that joint is bedded/filled with some kind of goo.

I'll bet your boat has quarter-round moldings at the base of the cabin to cover the joint. Bedding that molding properly is the key to a leak-proof deck. You need to remove the moldings and inspect the joint. The likely fix will involve recaulking that joint with polysulfide and then installing new quarter-rounds, bedding liberally in a waterproof goo.

If that doesn't work, don't blame me. My advice is barely worth what you pay for it.

[ 10-01-2002, 05:04 PM: Message edited by: Scott Rosen ]

[Ian G Wright]

Originally posted by Scott Rosen:
Finding deck leaks ain't rocket science.

A teak on ply deck can only leak at the plywood joints. There are really no other possibilities.I'm not saying anything,,,,,,,,,, not a word,,,,,, but Oo it's hard,,,,,,,,

IanW ;)

[Bob Cleek]

Ah-ha! Case made for traditional planked decks without plywood underlayment. (Bronze strapping provides the rigidity desired in such cases.) Now, a traditional planked deck will ONLY leak directly above YOUR berth and ONLY when you are in it, unlike plywood decks which will leak just about anytime water hits them. Scott's right. Ply decks can only leak below at the plywood joints, until the ply rots through completely. Problem is, they can leak above from just about anywhere, run along the ply until they find a joint, and then down. This may or may not be above your berth. Start with the trim. I'd use Dolphinite bedding, though. Liberal amounts. Stay the hell away from polysulfide sealers. You'll never get the trim up without destroying it the next time you chase a leak. And there WILL be a next time. Get used to it! LOL

[Ian G Wright]

Originally posted by Bob Cleek:
Ah-ha! Case made for traditional planked decks without plywood underlayment. (Bronze strapping provides the rigidity desired in such cases.) Now, a traditional planked deck will ONLY leak directly above YOUR berth and ONLY when you are in it, unlike plywood decks which will leak just about anytime water hits themWhat Bob said,,,,,,,,,,
Now I'm not one to say I told you so,,,,,,,,,,,,,, but I am tempted.

[Scott Rosen]

It's true, plywood decks are an inferior sort of thing for an inferior sort of sailor. But as long as you don't own a fiberglass dinghy, you should be okay with the wooden boat gods. A plywood deck may earn you a short stay in purgatory, but a fiberglass dinghy will earn you a long stay in that place where the sun don't shine.

[Ian McColgin]

Now don't go knocking my $20 glass dink.

Anyway, leaks around cabins and carlins and such are pretty much straight down - If the drip's under the hatch combing, there you go.

I once tried sealing up Goblin's deck and trunks and whatnot enough to blow air up sudsey water - like looking for a leak in a tyre. Like that repeated line in "The Ghost and the Darkness" between Val Kilmer and Michael Douglas,
"I tried that also."
"Did it work?"
"Well, no. But it was a good idea."

Large plastic garbage bags slit and folded out and secured with duct tape are excellent berth protection. . .