Drying an internal core out

[Canopy Locked]

Look for ideas and advice from folk who've had this problem

5m boat - with one piece fibreglass deck (not wood) has a wet foam core.

It's definitely in the stern section, but can't be certain that it does not extend further forward. The wet foam is still very hard and solid so I will not be ripping the deck up, but I was thinking about using a dehumidifier with a ducted blower, to blow warn dry air under the deck and hopefully allowing the moisture or significant amount of it to escape.

The boat is in a building and I guess could be "wrapped" in plastic sheeting to enclose the dehumidifier a bit more.

Ideas, experiences would be very welcome
Cheers
Rob

 

[BabaYaga]

I was thinking about using a dehumidifier with a ducted blower, to blow warn dry air under the deck and hopefully allowing the moisture or significant amount of it to escape.

Unless you expose the wet core to the atmosphere in some way, I think that would be an extremely slow process.
The water will likely have entered the core through tiny openings (screw holes etc) over a long period. Reversing this by applying heat, forcing evaporation through the same small openings, will take a very long time IMHO.

 

[coopec]

Rob
What is the "wet foam core material"!!

Is it balsa, Klegecell, Divinycell or maybe Airex? Can you tell us that? ?
"The wet foam is still very hard" leads me to think it is not balsa.

We know your boat is 5m but what make?.......

 

[geem]

Some cheap core is just blown expanding foam. It has open cell foam structure. It gets saturated very easily. Good marine construction rigid foam board is closed cell foam and doesn't absorb water easily. I suspect if the core is saturated it may not be closed cell. Lots of small dinghies used to be built with an internal and external moulding with the void filled with builders expanding foam. You need to give us a little more info on construction

 

[Canopy Locked]

Apologies - I think it's closed cell foam. It's not soft, where it's wet. I have cut away a corner in one compartment to make a sump and have been pumping out the water (manually) as it fills. The boat is sitting bow high as I have the trailer jacked up at the front, hence water is naturally making it's way aft.

I attach some pics of the boat structure. The 2 compartments that have water are the 2 stern quarter ones. I can feel down the side of the boat, just under the throttle to where the cockpit skin meets the deck - I can feel moisture on my finger tips .

My plan is to cut an inspection hatch in the forward lockers in the cuddy (these can then have a simple plastic inspection cover fitted.) and possibly one in the port side of the cockpit. From here i was thinking that warm air ducted down under the deck might help dry out - maybe use a dehumidifier? It's most likely that it's the outer compartments that have got water - The stern quarter compartments are open to the air

In the pic of the boat, you can just see the water just behind the fire extinguisher bracket. It's the same on the opposite side.

The boats in a shed but I'm guessing that I'd need to make a tent over it if I was to use a dehumidifier.

Obviously the other part of the problem is finding where the water is coming from, but I'll cross that bridge once I have dried the worst out