Can you get rid of water in foam flotation, and if so, How?

FrankyZ

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I have a 2001 Mako 192 with foam flotation from the factory. I believe the boat may have water in the flotation. I have not yet weighed the boat and the manufacturer says boat weight is 1950 lb. If I have water in the flotation is there any way of removing it without pulling the floor and removing the flotation?
 

Scott Danforth

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The only way to get water out of foam is to remove the water-soaked foam and replace it
 

airshot

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Here is a story about a fellow that claims he dried his out, the story is that he attached a vacuum to the drain plug hole then passed heated air under the floor until the foam dried out....the vest part of this story is he hadvthis hooked up all winter long!!! Yep...for 6 months continous before the foam finally dried. How true, I have no idea but have read this story numerous times on a variety of boating forums. Would it be worth it ???
 

ejnichol

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The only way I could see working involve sealing boat in some type of air tite bag and hooking up a vacuum pump to draw negative pressure.

This would cause other issues and take quite some to boil off the moisture. Crazy idea right?
 

Baylinerchuck

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The question is how did the water get in there? Also how long was it in there? If the foam is absorbing water, the cells of the foam are open and it needs replaced. You’ll never get all the water out, no matter how much you try. The foam will keep absorbing more.
 

jbcurt00

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Yep, before water intrusion rigid foam was closed cell

After water got in, freeze/thaw burst the closed cells, it now has thousands (Tens of? Hundreds of? Millions?) of tiny pockets of water
 

tpenfield

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There is dryboat.com, which essentially attempts to remove water through suction and evaporation.

As mentioned, the results may be quite temporary if water can readily re-enter the areas that were saturated. Flotation characteristics of the foam probably would not be restored, since the closed cell nature of the foam has probably been destroyed.

I tried to dry out my previous boat, which had a soggy bulkhead. The problem being that it is tough to create the environment that will dry the boat out. In most practical situations it is easier to remove the old/wet and replace new/dry.
 

FrankyZ

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Here is a story about a fellow that claims he dried his out, the story is that he attached a vacuum to the drain plug hole then passed heated air under the floor until the foam dried out....the vest part of this story is he hadvthis hooked up all winter long!!! Yep...for 6 months continous before the foam finally dried. How true, I have no idea but have read this story numerous times on a variety of boating forums. Would it be worth it ???
This is pretty drastic in my view, however, if it worked tha man is a genious!
 

FrankyZ

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The only way I could see working involve sealing boat in some type of air tite bag and hooking up a vacuum pump to draw negative pressure.

This would cause other issues and take quite some to boil off the moisture. Crazy idea right?
 

Wildey

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Nov 24, 2021
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It would work. Basic meteorology explains it. But, what a waste of time and effort. It would be akin to filling you foam space with car wash sponges. Nice and dry ..... but extremely thirsty and over anxious for the first sip !

Brief hijack .....may have been posted before.
What would be the problem (if any) of sealing the flotation areas completely, leaving an inspection port of sorts to occasionally check for water intrusion ?
Similar to the preflight inspection of a seaplane. Or, the hollow, empty pontoons on a pontoon boat. The cavity(s) could be sealed as well as a fuel tank and checked / siphoned as needed .. if ever needed. Pay attention to the waterline as an indicator ? Flotation only needs to work for , how long ?
Till you're rescued ? towed in ? Hours, weeks ? It could even leak a little.
Just wondering.
Please excuse,
Thanks
 

chevymaher

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Here is a story about a fellow that claims he dried his out, the story is that he attached a vacuum to the drain plug hole then passed heated air under the floor until the foam dried out....the vest part of this story is he hadvthis hooked up all winter long!!! Yep...for 6 months continous before the foam finally dried. How true, I have no idea but have read this story numerous times on a variety of boating forums. Would it be worth it ???
I remember that guy he put a deck over and sold it as restored.
 

flashback

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Jun 28, 2002
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I have an idea, cut a few holes in the foam cavity and turn loose with a roto rooter pulverizing the foam, then shop vac the crap out and install inspection plates in the holes....and leave it empty, I don't like foam.. LOL
 

Scott Danforth

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I have an idea, cut a few holes in the foam cavity and turn loose with a roto rooter pulverizing the foam, then shop vac the crap out and install inspection plates in the holes....and leave it empty, I don't like foam.. LOL
However many boats rely on foam for added structure
 

Scott Danforth

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Yep I know, but it's a shame. Tremendous waste of space but the law requires. it's a poor excuse for structure..
Carolina Skiff and Boston Whaler would not exist without the foam
 

zool

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Aug 19, 2012
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3,432
It would work. Basic meteorology explains it. But, what a waste of time and effort. It would be akin to filling you foam space with car wash sponges. Nice and dry ..... but extremely thirsty and over anxious for the first sip !

Brief hijack .....may have been posted before.
What would be the problem (if any) of sealing the flotation areas completely, leaving an inspection port of sorts to occasionally check for water intrusion ?
Similar to the preflight inspection of a seaplane. Or, the hollow, empty pontoons on a pontoon boat. The cavity(s) could be sealed as well as a fuel tank and checked / siphoned as needed .. if ever needed. Pay attention to the waterline as an indicator ? Flotation only needs to work for , how long ?
Till you're rescued ? towed in ? Hours, weeks ? It could even leak a little.
Just wondering.
Please excuse,
Thanks
Sealed compartments are used in bigger vessels that dont require foam. My 28 has them, but with limber holes leading to a center bilge with redundant pumps. There is also a removable plug midship, incase you need to drain the forward bilge to the rear bilge. None of the wood was rotted forward of the engine compartment in the rear.
 

Wildey

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Nov 24, 2021
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202
So the foam is a requirement ? I didn't know that. (small boat < 20')
I meant to say "non structural app" in my earlier post.
Anyway, with the smaller single hull boats commonly seen here, the original structure of the hull, stringers, bulkheads and floors are almost accidentally repaired to a degree far superior to the OEM attempt. (my bayliner, anyway)
The added strength of the additional FRP provides more rigidity than the original structural foam did.
 

zool

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Aug 19, 2012
Messages
3,432
So the foam is a requirement ? I didn't know that. (small boat < 20')
I meant to say "non structural app" in my earlier post.
Anyway, with the smaller single hull boats commonly seen here, the original structure of the hull, stringers, bulkheads and floors are almost accidentally repaired to a degree far superior to the OEM attempt. (my bayliner, anyway)
The added strength of the additional FRP provides more rigidity than the original structural foam did.
Since 1977, foam was required under 20' for new builds only, not reconstruction by us. Aside from deck support, it provides stiffness, soundproofing and allows thinner hull layups below the water line.
 
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