Home Depot Styrofoam vs Pour In Foam

[pete44]

Seen dozens of posts on going to use pink or blue styrofoam insulation to use instead of pour in foam...I have seen comments on "allowing drainage" to bilge area instead of foam that "blocks" drainage...Who out there has a method of installation of the foam sheets that "allow drainage" through contained areas?....Also, I read you can use the pour in foam but place a plastic cover before it meets hull that way the pour in foam never meets the hull thus leaving a gap for water/moisture to drain...Problem with the factory foam which many of us know it meets and bonds to hull and when I removed it it looked "dry" until I pryed it from hull (then wet underneath)....Opinions please

And lastly, How do you make your thread title in bold letters on this forum?

Thanks,Pete

 

[ezmobee]

Re: Home Depot Styrofoam vs Pour In Foam

How do you make your thread title in bold letters on this forum?

You don't. The bold ones are just the ones you haven't read yet.

I would think the foam boards would not typically be able to lay completely flat against the hull so there'd just naturally be drainage.

 

[bananaboater]

Re: Home Depot Styrofoam vs Pour In Foam

After cleaning out the drainage gaps I left a 4 inch gap at the keel line between the two sides of the pink foam. I hot glued the other layers of foam so they would not slip down.

 

[erikgreen]

Re: Home Depot Styrofoam vs Pour In Foam

You have to leave a gap.

Regardless, the foam is going to retard drainage.. it's the way it is.

The best idea I've seen so far is installing a "tree" of pvc pipe with holes drilled, so water only has to travel a couple feet before getting into the pipe and getting out of the area.

Erik

 

[HopeSheFloats]

Re: Home Depot Styrofoam vs Pour In Foam

My plan is some 'quarter inch or so' dollops of pl or 5200 placed here & there to space the foam away from the hull..... But what do I know? I bought a Holiday thinking I'd be able to just sit back and enjoy floating

 

[mmd5]

Re: Home Depot Styrofoam vs Pour In Foam

I've been thinking about using some basement floor underlay that is a dimpled design to allow drainage. It would appear to allow an escape path for water under the foam. A couple of pictures are attached.

 

[cc190cc]

Re: Home Depot Styrofoam vs Pour In Foam

Dont go to crazy, you are not going to get the sheet foam in there so well that it will hold water trust me. The poor in foam basically fills 100% of the area, not allowing drainage. I cut and installed mine to the best of my ability and there are natural drainage gaps everywhere.

Also, most water is directed to the center of the boat where there is probably a drainage channel, at least mine is this way. There is no foam anywhere around this channel on mine.

After i installed the pink foam, and pool noodles, i used right stuff spray foam to fill in gaps and tie it all together. It came out incredible, i only used the right stuff on the top, where the foam meets the deck.

Check out the most recent pics on my photobucket page from this weekend, you will see what i did for foam.

P.S. Pool noodles work great. 1 noodle can float a 200 pound man, my boat weighs 1800 pounds loaded. I have 10 noodles and 4 2X8X2" sheets of home depot foam board. I figure it could float 2 of my boats.

http://s884.photobucket.com/home/cc190cc

Chad

 

[tschmidty]

Re: Home Depot Styrofoam vs Pour In Foam

Actually you're calculations are way off on the floatation. It's all about displacement. A 200lb man is pretty darn close to floating, so only requires a few pounds of floatation to not sink.

Displace 1 gallon of water = 8lbs, or one square foot = 62 lbs. So your 4 2x8x2" sheets = ~5.33 square feet, or 333 lbs of flotation. The 10 pool noodles are maybe 2 - 3 sq feet (probably not that much) so maybe 500lb floatation total.

That said, I have no idea how much you actually need. You're probably fairly close in that you have enough floation to keep it from being submerged, but an actually coast guard calculation qould be what you'd need to do, which gets fairly complicated.

And right stuff is not a great choice since it is an open cell foam and will absorb water, but how you have used it on top you are sort of just using it as glue and I don't see a problem with it since I would think it would drain from there (others may disagree).

 

[CarTuner]

Re: Home Depot Styrofoam vs Pour In Foam

Actually you're calculations are way off on the floatation. It's all about displacement. A 200lb man is pretty darn close to floating, so only requires a few pounds of floatation to not sink.

You're exactly right. Tie a 25lb weight to a pool noodle and put it in the pool. Now tell me if the noodle is floating and keeping the weight off the pool's bottom

The other thing to consider is where this flotation foam is going to support the boat from. What I mean is, if the foam sheets (or pool noodles) are left loose between the deck and the hull, and the hull floods with water, the flotation foam will start to float and put upward pressure on the deck. The deck will then have LOTS of upward pressure, as it will be supporting the entire weight of the boat.

So you have to ask yourself....is your deck's install strong enough to support the entire boat's weight? Can you lift your boat by attaching to the deck and lifting up? Or will the deck rip apart if you try this?

Pour in floatation foam adheres to the stringers, bulkheads, hull, and deck. Out of 6 sides of a foamed in compartment, 5 of the sides are structural (stringers, bulkhead, hull), and only 1 is the deck. These structural pieces are designed to support the weight of the boat, thus the pour-in foam puts minimal upward stress on the deck.

The bottom line is that sheet foam and pool noodles are not a proper flotation solution unless the deck is designed to support the entire weight of the boat.

 

[cc190cc]

Re: Home Depot Styrofoam vs Pour In Foam

Greetings,

Makes sense (i feel stupid and smarter at the same time), I used the right stuff for a glue and to keep any loose foam from moving around, squeeking.

If the right stuff i used were to get wet, that meens the deck would be basically submerged, wont happen.

Thanks

chad

 

[Mustang77]

Re: Home Depot Styrofoam vs Pour In Foam

I stood my pink sheets on the side in stead of lying them flat..then i could angle the contours on the bottom..they fit really tite. That way the water could drain out. Also installed limber hole..

 

[North Beach]

Re: Home Depot Styrofoam vs Pour In Foam

Well if you only attached your lifting device to a couple of points and point loaded the deck it probably wouldn't lift the boat. But with the foam applying pressure over the entire surface of the deck it should more than well provide enough flotation.

I don't think that half thought out scenario leaves us with a feeling that bottom line the sheet foam is not the right material to use.

So just keep pouring that junk into the bilge of your boats and let it suck up all that water, close off the drainage, and leach out chemicals that eat metal.

Folks, the manufacturer's are not trying to build boats that last 40 plus years. And the danged PIP is way easier to install on an assembly line. It doesn't take a rocket scientist to figure out why we're finding all that wet sloppy crap in these boats when we do our restos.

 

[Triton II]

Re: Home Depot Styrofoam vs Pour In Foam

It doesn't take a rocket scientist to figure out why we're finding all that wet sloppy crap in these boats when we do our restos.

Probably an attempt by the manufacturers to improve sales by being able to say "our boats have positive floatation." Over here some manufacturers fill every void with styrofoam to try a spruik that their boats will float even when fully swamped, others don't bother. As North Beach says, pour in foam will eventually get water logged and be about as useful as a chocolate kettle.