Perplexing Moisture Problem

[Steve Mannshardt]

Hi all,

So, I have a 53' YF .

In the forward upper berth at the lower outboard corners of the fore and aft bulkheads we have moisture at random times. Its not much more than a sweat rather than standing water. The boat is currently on the hard dor refit and it doesn't need to be be raining. It's as if the cooling of the day is enough for this moisture to appear.

The forward ports were replaced as they did leak. The windlass leaked and was rendered. We also found that the hull deck flange caulking had gone bad with age. Compressed air could be heard leaking through the joint.

From above, the deck sounds good and solid when sounded.

I'm not ruling out a coring problem but am struggling to understand why the moisture would not be at the bottom corners of the bulkheads and not higher...

Thoughts on why and solutions to dry this out are appreciated. For the weekend, the forward cabin will be closed up with a big dehumidifyer running.

Thanks all

Steve

 

[Steve Mannshardt]

Discussed with the yard and have the cause and solution figured out.

 

[Fanfare]

On my 50MY the problem was stuffing the bow into rough seas which put tremendous pressure on the water and squirted it into all sorts of strange places. But the biggest mystery was why water came into my upper berth. It wasn't the ports. The berth structure is really a rectangular box beam reinforcing the bow and transmitting pressure back to the stringers and bulkheads. It's hollow inside. On my boat there is a lower rub rail which is throughbolted to the hull inside the berth. The sealant had failed on the bolts and it took me a long time to figure this out. I wanted to share this great revelation with you, but when I checked the brochure section I found the 53YFs don't have my rubrail. Drat! Another great solution foiled. Nontheless, the principle holds. Big waves = strange leaks in odd places. Maybe this can help.

 

[Fanfare]

Another possibility is condensation. It's not much of a problem for me in warm Florida, but became one when we took Fanfare to Nova Scotia. Most of our boat is framed in wood. The curved sides of the bow stateroom, however, are just the fiberglass of the hull covered by a thin layer of textured plastic. When we got to the cold northern waters condensation and mold started here, particularly behind the wall side of the mattresses. With a solid fiberglass hull there is no insulation. So the temperature varies quite a bit, and, being next to the galley, there may be more humidity than in the rest of the boat. Plus this cabin gets the least use except when grandchildren are present. Who are themselves perhaps more humid than adults.

You may have an air conditioner that could drip here as well. And don't forget to be sure its drain pipe is clear.

 

[dsharp]

Discussed with the yard and have the cause and solution figured out.

Where was the moisture coming from?

 

[Steve Mannshardt]

Hey all,

Sorry for the delay in responding.

So, this boat has been completely gutted for refit.

Prior to doing so the moisture on the bulkheads was evident. There was a 1/4 round aluminum batten nailed to the plywood of the upper fwd berth to keep the padded vinyl hull lining in place. It was badly corroded to the point that it has dissolved into pieces. Clearly salt water corrosion.

I started pulling the vinyl back and it was pretty clear that the foam was damp and had been for a while.

All of this soft material was pulled out and pitched.

As far as I can surmise, the leak was from a number of areas.

The forward opening ports leaked. Ports were replaced with new OEM from Steve at Sams.

The windlass leaked and was rebedded.

After some additional discovery we found the caulking on the hull deck joint was no longer competent and allowed for leaks. Prior to picking it out we put compressed air to the joint and you could hear air leaking past the hull deck flange at the fwd berth.

After all of these items were tended to the damp spots would show up randomly. The boat is on the hard and it's not been raining.

We put a moiture meter on the deck and the coring appears sound.

At the bulkheads the moisture reading maxes out, but only in a 12" by 4" area.

The logic is the leaks had permeated the foam and by gravity the water propagated to the lowest point. With the bulkheads being Aframosia ply, I expect the open grain of the end against the hull was able to wick moisture.

So, although leaks have been fixed, ambient temp and humidity will bring the moisture to the surface of the wood.

The varnish lady is beside herself over this as she needs to get into the fwd cabin.

Because I don't want constant moisture against the berth cushion for multiple reasons, the discussion with the yard is to epoxy afromosia veneer in this area as it will be covered when the berth cusion is in place.


Thoughts?

Steve

53' YF Resolution