Getting water out flotation foam

[theoldwizard1]

So any one who has owned a boat that requires flotation knows that over time the foam under the floor tends to hold water. Every time I see an uncovered boat in storage I know that that the bilge is full of wet foam and the floor, stringers and transom are probably rotten.

Prevention is the best solution. Storing with a cover or better yet inside (I have inside storage 6 months a year) is the best you can do. Well if you live in the midwest/northeast, you have probably been inundated with the rain we have had this week. We had about 6" inches over 2 days and I did not have my cover properly secured so most of the rain went into the boat. Yes, It is stored bow up and the drain plug is removed.

Well 4 days later, I was doing some maintenance and found that the foam under the floor was still pretty damp. We have had nice sunny days and the cover was off (until tonight) trying to get things dried out.

Is there any way of completely drying out the under floor foam short of storing your boat in a "kiln" of sorts (90-100F and 10-20% humidity) for a few weeks ?

 

[metriccrescentwrench]

How damp is "pretty damp"? Is it to the point that if you press on it water comes out?

Water doesn't get into flotation foam in just a singe incident, it takes months or years of exposure. And once it gets wet it stays wet, it's closed cell foam and won't give up moisture easily.

 

[jbcurt00]

IMO, once water logged, flotation foam is no longer closed cell. The cells have ruptured, and are now open. So as flotation, dry or wet, it is no longer as buoyant as it was............

Unless you use a fairly substantial vacuum kiln, IMO, a few weeks (or months) of low humidity, heated, covered space won't do much for you either.

As I mentioned, I don't think the foam will be closed cell any longer and it won't be as buoyant as it once was. There's not a lot of excess flotation capacity in a boat, if they skimp on the plywood and fiberglass knowing that the foam will add hull and deck stiffness. So I doubt a buoyancy drop of 15% would leave a sufficient amount buoyancy remaining to be meaningful. And I'd bet the now 100% dried (if possible, which I also doubt) foam has lost more then 15% of it's buoyancy.

 

[Vintin]

Shucks! I just picked up a large piece of dock flotation foam and it must weigh about 250 lbs. I was hoping to let it dry in the shop for a while and then cut it up for boat flotation for a FeatherCraft.

 

[jbcurt00]

Yeah, it might float, but it's not floating nearly as high in the water as it did long ago ^^^

Have you had the seat pan out of your FC's? If that's where you wanted to stuff the dock float, get the pink/blue XPS (NOT EPS) insulation at HD/Lowes and cut them to go inside the bench seats.

You might cut it into thinner sheets and see if it'll dry out, but it's not likely actually 100% closed cell foam, even if it was originally. The water HAD to go somewhere to add the weight, right?

 

[NYBo]

The only way to do it:
1. Remove foam.
2. Place in Dumpster.
3. Replace with new foam.

 

[ricohman]

My buddy was in denial about his wet flotation foam for some time. I ket hearing his drying rituals and test methods.
3 years later he is back on the water after a complete replacement of foam, stringers and transom. With soggy foam you get soggy wood. No way around that.
We learned a lot on that rebuild, but it will be the last glass boat I work on. Maybe a tinny though.

 

[MH Hawker]

I would suspect that a vacuum is the only way to remove it, thats how we dried transformers and that often took weeks. We used to apply a - 8 to - 12 psi.

 

[dozerII]

During my 1st rebuild on an 81 Marlin a chunk of saturated foam (the size of a baseball) that was being removed rolled under the work bench to a far corner. 16 months later when we sold out house and were moving out I found this ball of foam while doing the final clean, a good squeeze had water drip out of the ball. Pretty much proof it will not dry out.

 

[slag]

Every time I see an uncovered boat in storage I know that that the bilge is full of wet foam and the floor, stringers and transom are probably rotten.

That's quite an assumption and one I'd not likely make.

 

[jbcurt00]

That's quite an assumption and one I'd not likely make.

Read thru the resto forum Topics and you'd do well to reconsider that decisiion

 

[metriccrescentwrench]

That's quite an assumption and one I'd not likely make.

An uncovered boat sitting outdoors = a pretty good bet that it either has or will have waterlogged wood and foam.

 

[Chris1956]

To be clear, the flotation foam in boats manufactured by a reputable company is sealed from the outside world, by design. Rain and immersion will not saturate the foam.

Sometimes when seats and other fittings are installed, they are not sealed correctly. This occurs at the manufacturer, dealership or by an owner. This lack of seal can allow the floatation foam to absorb water. It also can rot decks, stringers, frames, bulkheads and transoms.

So, a boat uncovered in the rain or docked does not automatically have saturated foam. If there is some damage to the hull or deck, water can enter the foamed space and cause problems. Closed cell foams mitigate absorption, somewhat.

 

[Scott Danforth]

The only way to do it:
1. Remove foam.
2. Place in Dumpster.
3. Replace with new foam.

that is about it. wet foam will not dry

 

[jigngrub]

So any one who has owned a boat that requires flotation knows that over time the foam under the floor tends to hold water. Every time I see an uncovered boat in storage I know that that the bilge is full of wet foam and the floor, stringers and transom are probably rotten.

Prevention is the best solution. Storing with a cover or better yet inside (I have inside storage 6 months a year) is the best you can do. Well if you live in the midwest/northeast, you have probably been inundated with the rain we have had this week. We had about 6" inches over 2 days and I did not have my cover properly secured so most of the rain went into the boat. Yes, It is stored bow up and the drain plug is removed.

Well 4 days later, I was doing some maintenance and found that the foam under the floor was still pretty damp. We have had nice sunny days and the cover was off (until tonight) trying to get things dried out.

Is there any way of completely drying out the under floor foam short of storing your boat in a "kiln" of sorts (90-100F and 10-20% humidity) for a few weeks ?

Have you taken a core sample of your foam to see if it's saturated or just wet on top?

It takes months or years for closed cell urethane foam to saturate and it has to be in constant contact with water over that period of time. This is from a place that sells urethane foam, from their FAQ section:

[SIZE=-1]14. Is this foam water resistant?[/SIZE]

[SIZE=-1]Yes, but with the following caveat. The foams that we sell are considered closed-cell, which means that each cell that makes up the foam structure is completely closed off from surrounding cells which prevents it from acting like a sponge. It is completely safe for this foam to be in contact with water for hours/days/weeks and even months with no adverse effects. However, it should never be submerged in contact with water permanently. Over a period of years the water contact can begin to soften the foam and cause it to lose its closed-cell status. [/SIZE]

Core your foam, if it isn't saturated dry the top of it off and go about your business.

 

[allteriorconstruction@gma]

Well I've never tried to dry a boat, however I am certified in mitigation and water restoration.... And I have dried many of hardwood floors pulling the water back thru the same way that it entered and I'm pretty confident that I can access it from the topside drill some ½ holes in the saturated area and completely dry within 72hrs which is typically how long it takes to dry out a house that has had major water damage from trees on the roof or busted water lines... Either way if the water can get in there.... I can pull it out with a couple commercial dehumidifiers with hose attachment and a desiccant....pump the dry air to it with an air mover and close the doors or even build a chamber around it if necessary... it'll get up to bout 120°f + and let it eat

 

[GA_Boater]

Well I've never tried to dry a boat, however I am certified in mitigation and water restoration.... And I have dried many of hardwood floors pulling the water back thru the same way that it entered and I'm pretty confident that I can access it from the topside drill some ½ holes in the saturated area and completely dry within 72hrs which is typically how long it takes to dry out a house that has had major water damage from trees on the roof or busted water lines... Either way if the water can get in there.... I can pull it out with a couple commercial dehumidifiers with hose attachment and a desiccant....pump the dry air to it with an air mover and close the doors or even build a chamber around it if necessary... it'll get up to bout 120°f + and let it eat

First, this thread is old and should not have been re-opened by you.

Second,

Well I've never tried to dry a boat

Third, come back when you have track record of successful dry boats with closed cell flotation foam when it doesn't dry out over years.

Fourth, it is closed.