To Foam or not...

[ChilliSpoons]

What if you poured the foam in small layers and let set up. Then you could have layers with hard outer edges where if one layer fails you still maintain the integrity of the other layers? Almost like bubble wrap?

 

[brutus]

What if you poured the foam in small layers and let set up. Then you could have layers with hard outer edges where if one layer fails you still maintain the integrity of the other layers? Almost like bubble wrap?

I am no expert in foam period, just an observation, first boat I own with foam in it, like I said mine as like 1/2 inch crust over and is hard as hell, the inside is softer a bit but there is no way in hell you can squeeze it with your hand like a wet sponge. I did core small 1-1/2” hole to run a macerator hose, I still have the core sample in my shop, I will dunk it in a pale of water just to see how much water it can absorb, this foam thing is got me stressing out now lol

 

[Foxsea]

Sorry to burst your bubble on closed cell foam. You see, it is a chemical reaction that causes the gas, which forms the bubble, that bursts, and forms more bubbles. Hence it is not really closed cell. If you look at Styrofoam SM, or a coffee cup made of foam, that is closed cell.

Both my baby brother and I have rebuilt boats and had to cut out water logged floatation foam. In my case the water logged foam added about 300 pounds over time. The stuff can hold ALOT of water! Trouble is, nothing will seal like a spray foam, and you always need floatation foam by law on boats under 28 foot. You can cut sections of Styrofoam SM, or white foam block, and put them in place and spray foam around to reduce the water logging effect, but either way, this is a problem with a humid environment over time.

Bigger problem on floatation foam where you have wood stringers is the moisture is always on the wood once it soaks. You could change over to composite material for the stringers, but that is expensive!

Either way, if something goes wrong and you do swamp the boat, you will be happy that you re applied floatation foam to the boat. That is a must do on every boat rebuild. There simply is no way to guarantee that an accident or rogue wave will not occur if you are on the salt long enough.

Drewski

Well, Drewski, you are right about a reaction forming bubbles. However, the bubbles in open-cell foam are interconnected like a sponge whereas closed cell foam bubbles lay side-by-side, like tiny balloons which you cannot burst. We have all been discussing closed cell foam here. It is very much vapor impermeable as well as being waterproof. Yes, WATERPROOF!
Drewski suggested using SM board which is closed cell and waterproof but white bead board is not, if you decide to go that route. For the very best results in all respects though, choose professionally applied, closed cell spray foam, as several members had suggested earlier.

 

[brutus]

I got some good news, and going to go to bed a bit smarter. I talk to a 25 year experience applicator about this foam thing, basically closed sell foam does not absorb water( high density) that stuff that gets water log is low density closed cell foam, one way to tell is if you can squeeze it with your hands LOL it is of lower density. High quality, high density closed cell foam is waterproof, even if you poke it , water will not penetrate. He told me proper application in boat cavity is to make sure the surface is rough sanded 60 grit before application so it bonds, he also said to leave this to the pro when it come to application, the 2 part stuff you can buy for do it your self is not the greatest idea lol

 

[FisherTim]

Hello,

I have a 1977 Double Eagle 206 I'm at the stage where I need to decide to foam under the floor or not.

When I pulled it up the foam was soaking wet. It was all taken out, and now I'm trying to figure out if it's worthwhile putting back in. I'm sure it's been discussed before but I haven't had luck finding the thread's.

Any input is appreciated!

Pictures attached of current floor state.

You appear to have a fairly serious rot problem in your stringers, I assume you’re going to replace them?

 

[BarkleySounder]

Just wanted to update that I took the advice above and had West Coast Spray foam come today and spray closed cell foam in the boat. Top notch job. Next step is to get the floor in and glassed up nicely!

 

[brutus]

Just wanted to update that I took the advice above and had West Coast Spray foam come toady and spray closed cell foam in the boat. Top notch job. Next step is to get the floor in and glassed up nicely!View attachment 68070

Nice

 

[Drewski Canuck]

I'm glad you did proceed with a professional foam applicator. The two part foam is not at all waterproof. All the same, I suspect that your boat length makes it mandatory that it has floatation foam in it. I believe the cut off for Transport Canada is 24 foot, though it may have changed.

Changing the Stringers out with new foam should give you another 20 years on that hull. With new gel coat, it will look very sharp.

Drewski

 

[myles]

Just wanted to update that I took the advice above and had West Coast Spray foam come toady and spray closed cell foam in the boat. Top notch job. Next step is to get the floor in and glassed up nicely!View attachment 68070

looks awesome, i wish i had paid for that kind of service.

 

[BarkleySounder]

Further to my last update, the excess foam was trimmed up, and my new DPI Marine hatches have arrived. I chose these over tempress as they stick out/up way less making them almost flush when installed.

The floor has been cut to shape, and is just about ready for glass and gelcoat. As you will see in the photo, two reinforcement plates have been glassed between the stringers for when I mount the passenger pedestal seats.

The pod and other aluminum work is also coming along!