Flotation for the floor

[Dcmoony]

I am thinking of adding a floor in my jon boat. I want to add closed cell foam for added flotation. My concern is the floor will not be water tight so if it rains or I get water in the boat will the foam keep moister under the floor or will it be able to dry out? Don't want any mold growing under the floor by it staying wet. Thinking aluminum sheet floor pop riveted down so lifting it to dry out would not be an option. Any thoughts on this?
Thanks
Darryl

 

[BigTerp]

Closed cell foam board from Lowes or Home Depot. I got mine from Lowes. I have a custom aluminum floor I cut from a sheet of .125" aluminum. It's certainly not water tight, but the closed cell foam won't hold moisture. The stuff I got from Lowes claims less than 0.1% moisture obsorption by weight. Good enough for me. The biggest thing to do, IMO, is to clean out your hull channels that run back to the bilge. What I did was take a pressure washer and a really thin metal rod to make sure I got all the channels unblocked and squicky clean before I installed my foam and floor. This way any water that gets under your floor will have an easy, unobstructed path back to the bilge. As far as mold goes, I don't think it will be an issue. I removed a good bit of foam from my rear bench to install a hatch. The bottom 1/3 of the foam was completely water logged. But no mold to speak of.

 

[Ranchero50]

Flotation in the floor should be more for sound deadening than flotation. You want the flotation high in the hull so it doesn't turn turtle when bad poop happens in deep water.

 

[nctlspider]

Great point Ranchero.

Thats why the foam in canoes is up in the ends (of course thats the only place to put it too). Once they go under, you can keep paddling them even when they are swamped 2 ft under. I don't know why I never made the correlation before!

 

[T Man]

Ranchero50 » Yesterday, 14:23[/url]"]Flotation in the floor should be more for sound deadening than flotation. You want the flotation high in the hull so it doesn't turn turtle when bad poop happens in deep water.

Bingo.

 

[thudpucker]

Whatever you put down there, and however you hold it down, make sure it wont float away if the boat capsizes.
My old Star Craft learned me a tough lesson over that issue.

It was very nearly a one-way trip when I ran into bad weather on the way back with nowhere to go but onwards. I got swamped. Took a big green one over the bow.
It filled the boat, and my floorboards all came up and the Foam floated away with the exiting water.
The Rivets holding the Braces down. The one's I couldn't see that were under the floorboards. All corroded from salt water, came loose under the pressure.

The Big horsepower Johnson 20 Hp and the Hi-flow Bilge pump made of a Washing machine Pump and a 12v Subaru Windshield wiper motor, saved the day. [-o<
I was sitting in Ankle Deep water for a long time till that all settled down.

 

[Dcmoony]

Good information, that's what I like about this site. Would have spent some money that I can now use on fishing tackle.