*****pink foam******

[txbandit44]

I have read several posts and build threads that talk about using the pink panther foan insulator board from (insert random home supply store). I have not seen anything that stated how much dead weight it will float. In true redneck fashion I did a little experiment in my motor test tank.

I used a 5 lb weight since I had it laying around for my DEAD weight. I figured 80 cubic inches of foam was a good starting place. So i cut out 2 4''x10''x1'' chunks from a 4'x8'x1'' sheet stacked them and zip tied them to the weight.

SANK like a rock. Need more foam

Figured I should double it. So added 80 more cubic inches. FLOATS with 40 cubic inches out of the water.

So I know 160 cubic inches will float 5 lbs for sure.

I took away 40 cubic inches to see what happened and it floats about a quarter inch under the surface.

Im going with a redneck math calculation of 150 to 160 cubic inches of the pink stuff to float 5 lbs.

I figure i need to float 1000lbs to be safe thats boat motor equipment ect. (yes i know not everything will have the same boyancy(SP))

So 1000lbs divided by 5 lbs is 200. 200 x 160 cubic inches is 32,000 cubic inches.

There are 4,608 cubic inches in a 4'x8'x1'' sheet of the pink stuff

So 32,000 cubic inches needed to float 1000 lbs divided by 4,608 would be just a hair under 7 sheets.

I dont see how 7 sheets of this stuff is going to fit in the boat. Im no mathmatician nor am I an engineer so if i have screwed this up someone pipe up and tell me.

 

[CaptainKickback]

Re: *****pink foam******

First, if you are going to fiberglass over it, those that use it indicate the resin eats the pink foam.

Second, how did you get to 1000 lbs? If that is partly FG, remember FG is only a little negative bouyancy. So you only have to compensate for a small portion of the FG weight.

Third, they make the expandable foam so you can use every nook and cranny to get the displacement you need. Can be tough to do with the pink stuff.

 

[txbandit44]

Re: *****pink foam******

I dont know what FG means..

1000lbs was a guess im figureing 300 -400 for the motor batts and trolling motor another not much gear to speak of that would be loose in the boat. Dont have a clue what the empty boat weight is.

I just know how much pink foam it takes to float 5 lbs of dead weight.

I wonder how much weight a can of spray foam will float.

 

[MichaelP]

Re: *****pink foam******

There is a sticky on the top of the restoration thread with FAQs. You'll find calculations for flotation check it out. One important thing to keep in mind is you need to figure out how much your boat weighs if it were under water.
To quote a fellow member..."If you build a boat and it sinks you don't get partial credit"

 

[txbandit44]

Re: *****pink foam******

Thanks MichaelP, I looked for the sticky you mentioned but im either blind and dumb or its not there. Could you paste a link? Im getting close to closing up the floor on my 73 SS and i need to get the faom in fast.

Thanks

 

[Pugetsound]

Re: *****pink foam******

Put as much that you can fit in there but try to leave a clear area for any water to get to the bilge pump. An extra piece of foam has hardly any weight to it at all. You will seal it in anyway so no worry how much you use.

 

[Jon Sob]

Re: *****pink foam******

Hey there tx ...... I think this is it.
http://forums.iboats.com/showthread.php?p=2444554&posted=1#post2444554