Does foam provide support

[beertech44]

Here;s why I ask. I have a 17 foot aluminum boam that I just removed the wood floor. There was foam under the floor all the way to the plywood. Basikly the whole area under the floor. It was all competely waterlogged. So I removed it. I was hopping to use the sheets of pink styrafoam from home depot since they don't hold water and im sure water will get back under there.. But im wondering if I need to use the foam you pour so the whole area under the wood is filled for structural support

 

[Laddies]

Re: Does foam provide support

You will need some kind of support for the floor, but it don't have to be supported by the foam, the manufactures do it for floatation and to save the cost of floor supports

 

[beertech44]

Re: Does foam provide support

could I use my home depot pink foam and fill the areas as full as I can them pour the other foam around it till its level with the boards

 

[Realgun]

Re: Does foam provide support

You could put the pink foam in the pour foam around it but, it would be better just to use the pour foam. Thats what is made for. That Pink stuff was not made to float a boat it was made for insulation. If you really wanted the support you can use the 4Lb foam kit but you get half the foam for the same price. 2 lb foam is more than sufficient.

 

[beertech44]

Re: Does foam provide support

wont the new pour foam hold water

 

[Laddies]

Re: Does foam provide support

It should be closed cell and not absorb water

 

[martinmanfan]

Re: Does foam provide support

Actually, the foam under the floor is to support it and gain a flotation value...Most flotation is placed high in a boat for if she flooded, it won't capsize...<br /><br />Closed cell foam with a low density rating is what to look for...Be very carefull with the 2 part foams, for I have seen incorrect dosages applied that literally blew up trailers like a soda left in the freezer.

 

[beertech44]

Re: Does foam provide support

Okay my boat is a 1979 and the pour foam was completely waterlogged. Is the old generation foam different than the new pour foam I keep hearing called closed cell. I just don;t wantwater to splash in the sides and soak the faom again

 

[reka12]

Re: Does foam provide support

You can try this type of foam. The 8lb will provide great support and flotation. (each cubic foot of empty that will displace water will "float" around 64lbs. 8lb foam weighs 8lbs/cubic foot therefore if you foam in a cubic foot of space with 8lb foam you would theoretically provide 52lbs of floation). I don't endorse these guys, just a resource. There are others out there.<br /> http://www.shopmaninc.com/foam.html

 

[Realgun]

Re: Does foam provide support

Beertech you don't need the 8 lb foam USCG allows you to foam in a gas tank with 4 lb stuff. The newer foams are more resistant to water however no foam is water proof! Best thing is to drill a hole in the bottom of compartment to let the water out. The water will not stand in the compartment wetting the foam constantly.

 

[martinmanfan]

Re: Does foam provide support

I don't have the site handy, but the USCG gives the federal requirements of flotation placement for boat builders...It is not a good idea to put flotation under the floor...Drilling holes (for i.e.) through ribs to allow water to pass to the bilge area, is weakening the ribs...I have just replaced all ribs in my boat because the manufacturer did this and every rib failed...Place your flotation slightly below the waterline and above...

 

[JasonJ]

Re: Does foam provide support

Bear in mind that odds are very high that whoever owned the boat did not take proper care of it. No foam is completely water proof, but the current generation of foams are very resistant to absorbtion of water. The trick is in how you care for the boat. Keep it covered so rain and snow do not build up in it. When not in use, keep the bow elevated, drain plug out, and make sure water can drain adequetely under the foam to the stern. If the boat is to be left in the water, still cover it when not in use. It takes years of neglect to cause foam to saturate, it is not an overnight event. 2 or at the most 4 lb foam is all you need, good luck...

 

[cc lancer]

Re: Does foam provide support

Back in the 70's a lot of companies used insulating foam to save money, it was nothing but a sponge.<br />The boat I am currently working on only had a 1/2" penetration of water in the very center and no stringer rot.<br />The new polyester foam is extremely water resistant, a friend of mine floats 100 feet of dock on the new foam blocks.<br />Put the new foam in and don't cut corners, peace of mind is price less on the water.<br />JasonJ has some good advice in his post, follow it.