urethane foam

[Gian Milan]

wanting to put the bottles in a wooden template, there is the opportunity to fill them with polyurethane.
the cap should be closed with care.
The bottles become rigid. helps in case of collision.
If you use the bottles to stop requiring that make noise, they shall be fitted with silicone or glue.
WARNING!
the floating material, once closed lockers that cover, must be absolutely unable to get out!!
when the boat sinks, the bottles are put to push hard!
In addition to the required weight of the boat, be sure to calculate the weight of the load.

[therigwelder]

OK i figured i can get 18 cubic ft of blue Styrofoam into the sides of the boat and at around 55 lbs of resistance per cubic ft i will have right at a 1000 lbs of resistance.will this be enough to keep the boat in question safely afloat?

[Gian Milan]

calculation by the specific gravity

If you know that your boat is made ​​of a material that has a specific weight ... 2.8 (aluminum case) weights the boat, divide the weight by 2.8 to get the thrust of the boat upwards.
Engine and more should be placed in the shipment.
If your boat has specific gravity of 1.6 (our friends are sure, I have not seen the boat), boat weight, divide the weight by 1.6 and you push the boat up.

calculating the volume.

you start to measure the boat with great care.
You will get a measure in cubic feet.
cubic feet * 28 * 2.2 = lbs of upward thrust of the boat.

RULE

If your boat is made ​​from material with specific gravity less than 1 (eg cork), it floats on its own.
Much of the wood has a density less than 1.
The ships sank to the load, which could overcome the upward thrust of the wood.

[hoytedow]

Originally Posted by therigwelder

okay your suggesting that i fill the boat hull full of empty 1 liter plastic bottles.then deck and fiberglass over them.ok i understand the floatation principal but its rather unusual lol.one liter bottles are definatley cheaper than a&b part foam.I am a redneck from mississippi and i have to thank you for the good laugh i just got.wonder how it would work with aluminum coors bottles rflmao

No joke. Bottles are better and won't absorb water weighing down the boat.

[hoytedow]

Originally Posted by Gian Milan

my English is disgusting ...
maybe I'm the one who did not understand

Your English is improving.

[Gian Milan]

Originally Posted by hoytedow

Your English is improving.

I'm here for three reasons. 1) I want know what is happening in American society 2) I want to build a aluminium ca 10 meters and would like to discuss the projects 3) I must improve my English. 1 and 3. .. work in progess!

I was thinking about bubble wrap as valid float. We should put it in a polythene bag, welded o clsed with glue.

Even if idea to use polythene bags full of polyurethane and bottles is ....fashinating!

Someone use ping pong balls...

1 and 3. .. work in progess!

[therigwelder]

I decided to use pink foam board,i am posting pics.I put it in the bottom for now but i plan to foam the gunwales after i get the sole glassed in.I used 4 sheets of 4x8x1/2 foam.not really sure of the cubic footage to determine bouancy.can i use some "great stuff"foam to fill in any voids?

[tunnels]

Any of those two part spray foams will soak water for sure so dont do it !!

[therigwelder]

I figure i have 8 cubic ft.of foam.I figure that to be 440 lbs of flotation.I estimate i will place around the same amount of flotation in the gunwales giving me 880lbs of resistance and thats not counting the resistance of the boat itself.hopefully this is enough floatation to keep it afloat should a bad situation happen.What you all think?