Spray Foam?

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Adding foam will not increase your bouyancy, unless your boat is full of water. :LOL2: Foam is only to help keep your boat afloat in the event that you take on water.
 
huntinfool said:
Adding foam will not increase your bouyancy, unless your boat is full of water. :LOL2: Foam is only to help keep your boat afloat in the event that you take on water.

Thats what I mint. :)

So will spray foam work? I have a feeling at some point my beast might end up with water in it, and I would rather not recover it from the bottom of the lake.
 
It depends on what kind of spray foam you use.

Most all of it will absorb water, some of it just absorbs a whole lot less than others.

Any of it should add immediate bouyancy should the boat fill with water unless it has become waterlogged from repeated exposure.
 
exactly, closed cell foam will not absorb water (for a while) but most open cell stuff will and over time it'll make the boat heavier vs. without any. The 1/2" blue insulation boards from Lowes are closed cell. Sunk one in the kiddy pool under an anchor for a week and it didn't take on any water so that's what I'm using on my boat. I thought about blow foam, but I want to be able to remove everything to work on it down the road (think river rocks at 50mph...)

Jamie
 
Ranchero50 said:
exactly, closed cell foam will not absorb water (for a while) but most open cell stuff will and over time it'll make the boat heavier vs. without any. The 1/2" blue insulation boards from Lowes are closed cell. Sunk one in the kiddy pool under an anchor for a week and it didn't take on any water so that's what I'm using on my boat. I thought about blow foam, but I want to be able to remove everything to work on it down the road (think river rocks at 50mph...)

Jamie

Yea, I was going to use it under the fuel tank, and odd places like that just as a little filler here and there to tiddy things up. The Greatstuff I found is water resistant.

Foam boards under the decking is a good idea, and lets hope there does not end up a river rock in my lap at 50mph.
 
Be wary around the fuel, actually within 4" of the bottom of the hull has to be fuel proof per CG regs. You can encapsulate the foam board in fiberglass for these areas but it's a real PITA. Another consideration is the floatation should be around the upper hull so the boat doesn't turn turtle as it fills. The idea is that you can stay with the boat even if it floods with water vs. free swimming or holding onto the sides.

There's a lot of good info in the coast guards boatbuilders handbook. It's online, simple search will bring it up.

Jamie
 
Ranchero50 said:
Be wary around the fuel, actually within 4" of the bottom of the hull has to be fuel proof per CG regs. You can encapsulate the foam board in fiberglass for these areas but it's a real PITA. Another consideration is the floatation should be around the upper hull so the boat doesn't turn turtle as it fills. The idea is that you can stay with the boat even if it floods with water vs. free swimming or holding onto the sides.

There's a lot of good info in the coast guards boatbuilders handbook. It's online, simple search will bring it up.

Jamie

Yep, I was looking at that the otherday. Very good info. I am surprised there is not a perm link on the builders forums to it. Have not seen one post in the archives where anyone has done the bucket test to find out how much there boat will actually hold after all the mods and upgrades.
 

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