Floatation

More then the blue? or less then the yellow roofing foam?

I think that the denser the foam the less the flotation...wonder if you could weigh it with a known volume...and......just thinking out loud...


Matt
 
THanks.... grrrrrr..... :)

I am asking because I think it will be much easier to use a panal foam for the nose of my tdb than standing it on its bow and pouring in the 2 part urethane....
 
Phil:

I found this on the internet - hope it helps...

http://forums.iboats.com/showthread.php?p=2445257

Dan
 
Phil,

How would you keep the panel foam from bouncing around and out of the nose?

What about attaching a couple of come-alongs to the stern and raise it up enough to provide enough angle to make the pour foam work?
 
Thanks Daniel,

My question (or the flaw in the hypothesis) is that they are assuming all foam has the same floatation. Or am I splitting hairs...
 
I agree they did not go into the details of the actual foam buoyancy but I also checked the Owens Corning website and could not find anything there either.

What I was thinking was that if you could cut equal small sections of pink, blue and any other foam, float it in some water and then invert a digital scale on top, you could determine the amount of force required to submerge each and see the difference. The higher the reading the better the buoyancy.

Not sure it is worth the effort but should be roughly right.

Good luck

Dan
 
I was just going to layer the foam in tight... either using caulk to stick them together, or use a little 2 part foam to provide pressure.... then on the aft end of the compartment, an epoxied board similiar to the factory job.
 
Water density = 28 kg or 62.4 pounds per cubic foot

Foam board density = 1.5-1.7 lbs per cubic foot

So water density - foam board density = about 60.9lbs

Is the difference the amount of weight needed to sink the foam board to neutral buoyancy?

How many lbs of buoyancy is needed for your boat?

Matt
 
Thanks Matt for the info... I know on different density of urethane the boyancy changes, so I figured that the foam board may have a different density.


Ryan, I had thought of using the tractor loader to lift the stern to allow the urethane foam to stay in the bow... but that seems like a lot more work... I don't know.... just trying to make a better mouse trap... or at least one that is easier on my fingers...
 
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Phil,
I've been making burlapped decoys out of it, and they are very boyant! Since floatation is just the force from the weight of the displaced water, and the foam is low densitiy, it floats great. The biggest disadvantage I see is that gas and many other solvents chemicals will disolve it if not protected (and I can personally attest to what contact cement will do to it).

-Bill
 
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Another method would be to make a cheap form that is the same size/shape as the space in the bow you want to fill. Use 2 part flotation foam to fill the form. When cured, remove form. Then take the shaped foam and attach it using 3m 5200 to space in the bow you want filled.

dave b
 
I bought a few sheets of the pink foam board and cut them into "bricks". I then used 5200 glue to glue them into stacks under the bow and the stern of my Kara. Check out the attached picture.

You have to be careful about what kind of glue you use. We tried another marine glue (this one was clear) as a test and found that it dissolved the foam; the 5200 was inert. I left a 1 inch "channel" between the stacks to allow water to flow back towards the center of the boat.

View attachment IMG_0495.jpg
 
Anthony,


I couldn't help it....started laughing when I saw the pink blocks.....It reminded me of that discussion about flamingos and hunting ethics a few days ago (the one where some guys posted "silly" pics on another site)...

Maybe we can make flamingo "silhouettes" as well and get a multiple use product.....a decoy and flotation...


Matt
 
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