To foam or not to foam..that is the question..

Ok, here's the situation... We have the deck off the V21 now.. The good news is the stringers are fine. The bad news is the foam is soaked... it smelled like a cesspool. Voids in the foam, gallons and gallons of water trapped... ugh!.. The PO obviously never drained the bilge and never left the access covers off so things cound dry out when stored. We're in the process of removing it all now..

So here's the question.

Do I replace the foam or not? I know it acts as a sound absorber, and also as a stiffener... but is it really necessary? We've removed the rotten balsa wood that was the underflooring of the deck and laminated on 3/4 marine ply, then sealed and glassed over the whole thing so the wood is encapsulated. The floor sits on the stringers and is plenty strong so there's no flex, so do I really need the foam? (It's rather expensive and I'm guessing that I'll need about 20 gals of the stuff to refoam).

Opinions??:head:
 
I never had it in my 74 V, and they did not even put it in when they made the boat.
But when I took a 10 foot wave over the bow it filled the inside up to the gunnles and still floated!!
By what i read in another thread not long ago, the 21 has some sealed areas for flotation so with that news, and what i saw with my old boat, and the $$ your going to spend i would say go with out!

That said the coast guard has said all boats from the late 70's have to have flotation in them.
 
I've removed my foam and fuel tank and am planning on using only a minimum amount of foam needed around the top edges of the new tank to keep it secured. It won't have foam underneath or around the sides. There will be 2x4s across the top of the tank, beneath the floors, just as it was originally.
 
Destroyer, if it's not too much trouble, could you post some pics of your v21 with the floor off? I too have a v21 and would like to see what you are talking about. I suspect I'll have to do this someday. How'd you know you had a problem?
 
I can't imagine the relatively small amount of foam in the tank compartment would assist much in keeping a 21 afloat if swamped...certainly not if it's saturated...if foam at all, I'd follow Thacker's advise, but personally would find better way to secure the tank, leaving the foam out...MHO...
 
aw, if you are using pt 2x4's with an aluminum tank, you will need a barrier between the wood and the tank. that was the case with the older pt , not sure about the new yella stuff.
 
Having used foam I'd say definitely yes for you to use foam for the following reasons:

1. It adds floatation - a very, very good thing in case of swamping etc right ?
2. It adds sound deadening - less hearing the water under the hull, sounds more solid.
3. You've already corrected problems, so it won't likely get soaked again.

Assuming you've used foam before, and know how to use it, you'll do a careful job to avoid the pitfalls:
1. Pouring too much in a section, then dealing with the expansion issues.
2. Avoid getting the liquild on your hull surfaces - almost nothing stains worse.
3. Mixing too much at a time.

Finally, it actually contributes to the boat's structural integrity, less flex, more firm overall when the foam is used correctly and expands to a nice tight fit into specific sections.
 
Destroyer, if it's not too much trouble, could you post some pics of your v21 with the floor off? I too have a v21 and would like to see what you are talking about. I suspect I'll have to do this someday. How'd you know you had a problem?

Pics will follow shortly...meant to post them with the original post but had a problem with the camera. I didn't know I had a problem with the foam..although I did suspect it. When I bought the boat I knew the floor was soft. Reaching in under one of the access hatches I was able to pull out small rotted wood pieces from the floor and it was soaked, so I knew I'd have to replace the floor and probably the foam.

Spareparts said:
I stuff pool noodles in areas to act as flotation, if you can find them on sale, they are cheap and easy flotation

I've thought about that several times Spare.. Seems like a quick, cheap, easy solution...and with spring just around the corner they will be available in the stores shortly.


Bgreene said:
Having used foam I'd say definitely yes for you to use foam for the following reasons:

1. It adds floatation - a very, very good thing in case of swamping etc right ?
2. It adds sound deadening - less hearing the water under the hull, sounds more solid.
3. You've already corrected problems, so it won't likely get soaked again.

Assuming you've used foam before, and know how to use it, you'll do a careful job to avoid the pitfalls:
1. Pouring too much in a section, then dealing with the expansion issues.
2. Avoid getting the liquild on your hull surfaces - almost nothing stains worse.
3. Mixing too much at a time.

Finally, it actually contributes to the boat's structural integrity, less flex, more firm overall when the foam is used correctly and expands to a nice tight fit into specific sections.

I hate it when people are right and it costs me more money..<sigh>.. I have to admit that you're right Greenie....for all the reasons you stated. I'm already looking on eBay for closed cell foam kits.. Still not 100% sure that I'm going to go that route.. the pool noodles that Spare suggested are a good idea. Quick, cheap and they are closed cell also.. the only problem with them is the voids that using them would leave that poured foam would fill....but otherwise they are really a great idea... gotta think it over.

Hmmmm...here's a thought...I wonder if I could use both? A kit contains enough foam for 15 board feet..(1' x 1' x 1")... I wonder if I could pour some foam around several vertical round sections of pool noodle cut to the proper height...let it set ...(1 minute)... and then repeat the process if necessary to achieve the desired height. The noodles would act as a filler, and the poured foam should act as a binder and would fill the voids. They are both closed cell foam, so there shouldn't be a compatability problem there.. Might have to try a small test in a plastic bucket first..but it sounds like a workable solution.. anyone have any thoughts?
 
Not that it should make a difference...but what does gas do to a noodle?...I suppose if ya ever had to deal w/it, a melted noodle would be the least of yer problems...:zip:
 
Not that it should make a difference...but what does gas do to a noodle?...I suppose if ya ever had to deal w/it, a melted noodle would be the least of yer problems...:zip:

I have no idea. I know that gas melts Syrofoam, but I have no idea with it will do to pool noodle material. If, as I suspect, that the noodles are made out of polyurethane, then there probably will be no effect. Polyurethanes are not attacked by resins and they're resistant to gas and oil. They effect the foam only by a slight swelling after several hours of complete immersion when low density (1.5 to 2.O lbs. per cubic foot) types of foam are used. However, this quality of the low-density variety does allow it to absorb large quantities of water over a long period of time. (I'd be willing to bet that this is the type of foam that was origionally used in our boats.) Because of this, low density foam is not my recommendation for use below the waterline. For applications below the waterline, I think we should use urethane foams of 4.0 lbs. per cubic foot density or greater. At this density there is also no discernible impact on the foam from the hydrocarbon solvents such as gas or oil, and as an added bonus it will not absorb large quantities of water like the low density types do. I think a test block of pool noodle (say a 1" x 1" x 1" cube) weighed and measured carefully, then submerged in a pail of gasoline for 24 hours should prove or disprove it's use as foam floatation. If there is no decernable difference in size of weight, and the material doesn't soften, it should be ok for use belowdecks. :head:
 
Just take your time foaming it all in nicely and never mind messing around with pool noodles.

Do it right, close it all up, be happy.
 
Ok... figured out the problem with the camera. (I hope) These are a few of the pics of the foam problem. That black stuff in the center of the foam at the bottom of the holes is actually standing water. The wood is what was removed from the underside of the deck...totally saturated and rotted...falling apart.

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That is some fugly stuff there Destroyer. I like foam. It always amazed me how dry the foam was in my boat. Not much water absorption at all. If the foam was installed correctly I don't see how it got under the foam? I mean why didn't the foam bond to the hull and just fill the compartments to the top? Then why black water? was that contributed to by the rotten wood in the sole?
 
I would spend the $200-$300 and refoam. I was drum fishing one night in my 81 CC with the live well going not knowing it was leaking like a sieve. It wasn't obvious because my bilge was dry due to all the water running to the bow of the boat.

I only realized something was wrong once my livewell intake was above the water line.

I like to think that the foam occupied that space that the water would have gone before realizing I had a real problem in the middle of the Pamlico Sound that night.
 
That is some fugly stuff there Destroyer. I like foam. It always amazed me how dry the foam was in my boat. Not much water absorption at all. If the foam was installed correctly I don't see how it got under the foam? I mean why didn't the foam bond to the hull and just fill the compartments to the top? Then why black water? was that contributed to by the rotten wood in the sole?

Yes, I think you're correct on the wood staining the water. It smelled like a cesspool when first opened up... (UGH) As to how it got there... all I can think of is the PO never opened the hatches and let the poor thing air out over the winters. Once removed, if you look at the compartments that the foam is in you can see that they are all sealed from each other, so there's no bilge water that can flow from one compartment to another.... and I'm pretty sure that the hull was never submerged... so I just don't know.

One thing I'm going to do though is install a storage locker in front of the fuel tank. There's a big open area under the deck...just begging to be used.. so I'm going to put a hatch into the deck.... probably about 24 x 30 or so... (haven't taken any measurements yet). It will make a great place for an anchor locker or anything else I might care to put into it.

Anyways, my plan is to change all the hoses for the fuel tank... (they look good, but while it's open now it the right time to change them), install a new bilge pump and whatever else needs to be done, then fill the compartments with foam, reattach the deck, and then put down a rhino liner type of coating over the entire cockpit area. (It comes in white now). Then attach the radar arch, bimini, electronics, gauges, and engine and that should just about do it...:head:
 
One of the things I like about using noodles is they don't fill the entire space, it allows air to move freely around them, I don't care what you do, water is going to go where you don't want it, I put drain holes in each compartment that feeds to the bilge. if you get water in an area, it will drain to the bilge and not puddle in any compartment. The air moving around the noodle tend to dry it out. The V's have more than enough glass in the hull, they aren't using foam for any structural use. After owning two McKee's, and working on at least 100 Whalers, Scout's and McKee's over the years, foam construction ins't the best idea for combining with wood structure. I haven't seen a foamed boat yet that didn't have some water in the hull, that includes brand new ones that haven't even been put in the water
 
Yes, I think you're correct on the wood staining the water. It smelled like a cesspool when first opened up... (UGH) As to how it got there... all I can think of is the PO never opened the hatches and let the poor thing air out over the winters. Once removed, if you look at the compartments that the foam is in you can see that they are all sealed from each other, so there's no bilge water that can flow from one compartment to another.... and I'm pretty sure that the hull was never submerged... so I just don't know.

One thing I'm going to do though is install a storage locker in front of the fuel tank. There's a big open area under the deck...just begging to be used.. so I'm going to put a hatch into the deck.... probably about 24 x 30 or so... (haven't taken any measurements yet). It will make a great place for an anchor locker or anything else I might care to put into it.

Anyways, my plan is to change all the hoses for the fuel tank... (they look good, but while it's open now it the right time to change them), install a new bilge pump and whatever else needs to be done, then fill the compartments with foam, reattach the deck, and then put down a rhino liner type of coating over the entire cockpit area. (It comes in white now). Then attach the radar arch, bimini, electronics, gauges, and engine and that should just about do it...:head:

We're proud of you - keep up the good work.
 
destroyer, this is the storage i added under the deck between the cabin & fuel tank. lotsa room for buckets, bait nets, spare anchor ,etc. i like that i can stick my head down and look under the deck and also keep the channel clean under the fuel cell.

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this is looking toward the stern, under the built in deck locker,my fuel tank is in the very stern.
 
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