Floatation

[mskweres]

I am building a 15 foot boat from pwood. I want to put floatation in the floor and then cover it with another piece of pwood. Any ideas on floatation to use and where I can get it?

Thank you,

You can get 2-part pour in place foam from most marine supply stores. If not in your area, you can order it from stores such as http://www.defender.com/ or http://noahsmarine.com/ (in their pdf catalog)

Evercoat 2 part pour foam
http://www.evercoat.com/

Barrier Pour-in-place Rigid Polyurethane Foam.

Also http://www.rhhfoamsystems.com/

Remember that these 2-part pour in place foams expand quite a bit, so be sure to leave a vent hole. It sounds like you will be filling a fairly small area so you shouldn't have problems (except for the cost of the foam!)

You can also get 2-part pour foams from most places you buy fiberglas and resins.

[Nomad]

I favor 12lb and hight dencenty for silencing reasons, along with extra stiffness.

[djwkd]

can you still put cans and old driftwood etc in?

[djwkd]

although,i dont expect a reply to this...

[Ike]

Yes I have seen al kinds of stuff sunk into the foam. However if you really want to do this right, don't use pour foam. Go to abuilding supply and buy blocks of the foam they use in construction. I'm sure you've seen the stuff, it's blue, comes in big sheets about 4 to 6 inches thick. Cut it to size and put it down before you lay the floor. Then you won't end up having the problems that can occur with pour foam. See this thread Hull Flotation Foam Question http://boatdesign.net/forums/showthread.php?t=13679

[longliner45]

glass the compartments and put polyurethane foam in them, yes blocks of fome are good , and if you do use poured foam, be aware that the fome expands.

[Harry Kosta]

can somebody also answer this Q.
How much foam to you have to apply to get positive floatation?
Is to much foam bad or good?
Is there a calculation that shows you how much?

Sorry to ask so many questions on somebody's post.

Hazza

[antonfourie]

Harry 1L water = 1kg = 10cm X 10cm X 10cm, so if your boat weighs 1300kg you need 1300 cunic centimeters of foam, you will have to add the weight of the foam too. You are more likely to run out of space before you run out of weight to compensate for.

[Ike]

No you don't need that much flotation. First place the boat is wood which has a negative buoyancy factor (that is, it floats) so you need only provide enough flotation to float the machinery and the persons and gear weight.

Here's a link to a site that shows you how to calculate the amount of flotation you need. It's in pounds but easily converted to kg and cubic cm.
http://members.aol.com/spinners/flotdiag.html

[Harry Kosta]

Thank for the information guys.
That site is real helpful.
Clad I found this site with people from all offer the world interested in one thing, BOATS .

Hazza

[Crag Cay]

I presume this flotation is in case of capsize. You might want to 'google' stuff about inverted buoyancy. If you only have stuff under the floor, it does tend to invert the boat (turtle it) when capsized.

[djwkd]

i mean,inside a frame,can driftwood go inside a frame?

[SamSam]

Originally Posted by djwkd

i mean,inside a frame,can driftwood go inside a frame?

Originally Posted by djwkd

can you still put cans and old driftwood etc in?

No. No.