i have a jon boat, and with the ribs there will be alot of unused space. further more, if i customize it, there will be more dead space around the ribs.

does any have any recommendations on spray foam to aid in safety floatation?

thanks

EDIT:

A common solution for marine applications is a twopart urethane foam, also called pourable urethane and liquid foam. The two-part liquid, expanding urethane foam, is a closed-cell, pourable foam, which will resist the absorption of water. Once fully cured this foam can be laminated over with any type of polyester, epoxy, or vinyl ester resin without melting. This product can be poured in multiple coats.

As long as you use a closed-cell foam, it doesn't matter much.  It just fills a void with something light that won't allow water to take up the same space if the boat swamps.  If you remove the seats, you can use the foam the factory put in.  I cuts like butter with a good knife, especially an electric one.

As long as you use a closed-cell foam, it doesn't matter much. It just fills a void with something light that won't allow water to take up the same space if the boat swamps. If you remove the seats, you can use the foam the factory put in. I cuts like butter with a good knife, especially an electric one.

do you think household spray foam from a hardware store be any good for this application?

Just make sure you leave a channel for the water to drain to the back of the boat.

Just make sure you leave a channel for the water to drain to the back of the boat.

thanks for the tip

im going to leave the middle channel free, as that is the lowest part of the boat.

i think i found what i need...  check out the quote

I don't think the benefits will out weigh the cost and what ever you do don't mess with the factory foam under the seats.

The foam under the seat are your floatation  

Most floatation foams provide about 60 - 66 pounds of floatation per cubic foot and add about 2 pounds to boat weight per cubic foot.

Just be very careful when working with it.  It expands greatly and will literally rip your boat appart if you put too much in an area.  Don't think an enclosure is going to stop the stuff from expanding.

You also only have an extremely short time to work with it.   A drill powered paint mixer works great.  Add the two parts to a can, mix for about 5 or 6 seconds and and pour it.  It starts expanding in about 10 seconds.  It's better to mix a little a pour a coulpe of times than to try getting enough in a spot at one time, because I can't stress enough, the stuff will rip everthing loose if you get too much.