Flotation in seats

Just bought a pretty old 12' aluminum boat and trailer for a fixer-upper. This thing is quite a mess, no wood seat tops and seat frame tops are bent. Hull appears in good shape.
My question is this...I want to put flotation in the seats(3) but don't know if I should use poured foam or the blocks. I also read where the flotation should be only at the top of the seats. Wouldn't think that should be to hard with block foam( just glue it to the bottom of the wooden seat?) Is there a certain type of block foam to use and how thick should it be?
Also, if I put a floor in the boat,should I not put any flotation under the floor? Read where it would cause the boat to flip upside down if filled with water. Any help would be greatly appreciated. Thanks in advance.
....John

Re: Flotation in seats

I have an aluminum boat out the yard. Underneath of each of the three seats are one big block of foam. It takes up the entire area under the seat almost like they just use the foam as a form and bent the aluminum around it.
Naval logistics motto applies here - more is better.

Re: Flotation in seats

Blocks of "closed cell" foam are fine.

Be carefull installing a floor It can upset the center of gravity making the boat somewhat more prone to flipping over.

A 12' boat doesn't leave much capacity for modifications. The seat foam is a must.

Re: Flotation in seats

Thanks folks;
Is it ok to fill up the entire seat under the wood with block foam?

Re: Flotation in seats

I agree, but it sounds like you've never had the pleasure of stripping one that the manufacturer has turned into a "bass boat". They add a lot of weight at the top of the boat.

Re: Flotation in seats

jursting said:

Thanks folks;
Is it ok to fill up the entire seat under the wood with block foam?

Click to expand...

Yes. Just leave room, in the center, for drainage.