Tips on Finding a Deck Leak - 2007 Hunter 41DS

[dkinzer]

It has been raining very heavily for several days now in the Portland area. I was at the boat this morning doing some work in the compartment below the forward dinette seat and I noticed a small puddle of water on the floor. I shortly discovered that there is a small leak somewhere that is allowing water to run down the wall behind the forward seat and make its way into the compartment below. I have attached a photo with a hand-drawn yellow arrow pointing to where the water is entering from the ceiling.

Based on the location of the entry I suspect that water is entering through one of the deck penetrations around or near the mast. I'm looking for some suggestions as to how to go about tracking down the source and then, ultimately, stopping the leak.

I can see how to take down some of the plastic moldings in the corners but it's not clear how to take down the ceiling headliner. Does anyone have any insight into that?

 

[Don S/V ILLusion]

The typical way - Wait for a dry day and use a hose to discretely soak every suspect area one at a time to see which is the source

 

[Benny17441]

At that point of entry I would suspect the caulking in a deck fixture maybe fouled. A small puddle in a downpour likely means a small leak which may be somewhat difficult to find. First make sure all the screws that affix deck fixtures including stanchions and the bow pulpit are tight and reseal any suspicious caulking. These leaks usually travel along the inner hull or deck before showing so the point of entry is frequently at a different location. The points of entry are usually on the same side of the boat and forward towards the bow. Like others suggested you can use a hose and soak the area starting close to where the leak shows and move gradually towards the bow. I would not take down the liner but rather try to locate the point of entry from the outside where ultimately the fix will need to be applied.

 

[RoyS]

You can use plumbers putty to build a dam around suspect deck fittings. Fill the resulting pool with a cup of water and go below and watch. I would not attempt to remove the liner if I were you.

 

[sailcapt340]

On a friends 340 we did the technique Roy outlined. Same area, same ending point as you. We added some food coloring to the water. While we found loose stantion deck fittings, they were not the cause. We rebedded those.
We did find the source at the base of the mast deck fitting, same plumbers putty dam and food coloring. That water traveled the width of the boat somehow.
Looking closer at the caulking we could see dried and cracked areas.
He opted to drop the mast and rebed the fitting. It ended the leaked.
Removing the headliner is a whole other issue, think twice on that one.
Be patient, water has a mind of its own and won't travel as fast as you want it to.

 

[Nachismo]

Remembering that water flows downhill, you can pull the mast wiring access plate just forward of the compression post. I believe that’s the high point. If it’s dry, work downhill. Also, don’t fear headliner removal. Pretty easy to put back. I just use a plastic putty knife with the corners rounded off to jam it back in the channel.

 

[dkinzer]

Thanks. I did spot the mast wiring access plate, removed it and felt around inside as much as I could reach and didn't feel any moisture. It has been a bit drier than it had been when I first discovered the water incursion so I may have to wait for another very wet spell to investigate further. My fiber optic camera might be helpful for peering into small spaces.

 

[njlarry]

Never tried it yet but it has been suggested to pressurize the cabin with a shop vac or low power leaf blower and use soapy water around the deck fittings to find leaks in reverse path.

 

[dkinzer]

Finally! The leak has been located. The water is coming in at the forward outer corners of the two deadlights located about amidships. I've found a couple of posts about re-bedding the deadlights using Dow 795. I wonder, though, if there may be something I can do as a temporary measure to halt the intrusion. Suggestions?

 

[danm1]

I am embarrassed to admit I used wide waterproof tape `temporarily` in a similar situation. Successfully.

 

[jssailem]

Yes, you can do a temporary fix.

Lots of boat owners have done that. Cover the boat with a tarp... I have done that to get through a winter of storms and times gone from the boat. You can try caulk and goo and (forbidden) the bad word silicone .

Eventually like peeing in bed, you have to get up and clean the sheets...

The trouble with the fixes (other than the tarp) they can cause more damage that needs to be remedied before you can fix the actual problem. Buying a previous owners boat, you discover these types of issues and you wonder, what were they thinking.

Once you isolate the issue, set aside the time and fix it so you can enjoy the sailing and not be concerned in the next rain storm. Will this be the one that ruins my cushions or damage my internal wood work.

Just my thoughts. It is your boat and you get to make the choices.

 

[SEMPERAVANTI41]

Captain Tolley’s Creeping Crack Cure