Positive Floatation?

[Friends with SCAMPS]

I've got a fixer upper WWP14 that I'm beginning to fix up. It came with two big ugly blocks of hard foam that look like they previously were holding up the former owner's dock. I also bought a pile of kids PFDs for $20. So far I've cut the dock foam to fit up under the cockpit replacing it everywhere it looked like there used to be positive floatation. I'm also rebuilding the V berth area and will put more there. Where else makes sense to add positive flotation? Under the coamings? Can I put in too much? Thank you!

[TitusTiger]

I don't know the boat enough to give a good answer, but my different tack

http://www.jamestowndistributors.com/us ... o?pid=2198

is something you can use to fill in the nooks and cranies you want to add extra floation

[HappyDog]

Check Versi-Foam products, two part frothing kits in various sizes, 97% closed cell 2 lb/cuft polyurethane foam. I have used this and had good results. Flotation is best added up high where it will help keep a swamped boat upright.
C.

[TitusTiger]

Check Versi-Foam products, two part frothing kits in various sizes, 97% closed cell 2 lb/cuft polyurethane foam. I have used this and had good results. Flotation is best added up high where it will help keep a swamped boat upright.
C.

Does the extra flotation have any structural strength benefit --- ?

[HappyDog]

I used the sprayed in foam to fill the odd shaped spaces below an epoxy saturated plywood deck in a fiberglass runabout. The hull was just an empty shell from a 16' FourWinns when I started. I built an egg-crate style structure to support the deck which was filleted and glass taped to the hull. Most of the rectangular space in the egg crate was filled with cut slabs of styrofoam set in a thin bed of spray foam and the remaining irregular space was sprayed full of foam resulting in a deck that is still rock solid. The support provided by the foam completely eliminated any flex in the hull or deck. The ply deck was bonded to the egg crate with thickened epoxy and then covered with glass set in epoxy. I do believe the foam contributes a lot to the structure. Boat/deck is still going strong after ten years.
C.

[Friends with SCAMPS]

Everything I'm reading online says spray expandable foam leads to dampness you can't get at which leads to rot. And, I'd like to work with the foam I already have. If I do some forward, some under the cockpit, and under the coamings.. it seems balanced. I'll do some rough calculations of how much I need for the weight of the boat plus area if filled with seawater. I also read that too much floatation down low can lead to re-capsizing when/if it's swamped. Does anyone have experience with that sort of thing? I'd like to get some lower because of the centerboard trunk. Thank you for your thoughtful responses.

[TitusTiger]

This raises an indirect question for me.. I have a Paceship P-12... (I should track down the old brochure to see if it has positive flotation)... and I am wondering, do most boats need more positive flotation?

Edit: the brochure says it has positive flotation, but I wonder how much is enough

[Friends with SCAMPS]

I meant to mention, I bought this boat from a man who had been working on it. It was completely empty inside. So, I am not necessarily adding extra, only trying to put in what's needed. Although, I am wondering if there is a negative to more.
TitusTiger, As I understand it a cubic foot of sea water weighs approx 64lbs, so, adding your boat weight to the weight of open space that could be filled with sea water will give you a number to start with.

[HappyDog]

My experience with sprayed foam has been a good one. I suspect that there have been many cases of individuals using spray foam that was not closed-cell and that has led to the bad reputation for sprayed foam. Even CG approved closed cell foams will absorb some water over extended periods of time if exposed to liquid water. Care and planning are crucial, and isolating the foam from water is necessary. Sealing the inside of spaces to be filled with a couple brush coats of epoxy is a good practice just as is epoxy saturating any wood parts. Sprayed foam should not be applied to highly flexible surfaces as it will delaminate from structure over time and the broken surface is a pathway for water intrusion. It should also not be applied over through-hull or through-deck hardware.
Another avenue for adding flotation to odd shaped spaces is the use of Styrofoam Shipping Peanuts to fill closed spaces or in plastic bags for stuffing into areas where loose peanuts could escape.
Kindly post some photos as your work progresses.
C.

[Friends with SCAMPS]

Ok, I can't believe I'm letting you see this before I sand and paint everything white.. but here goes. One picture is of the cardboard patterns for the "Vberth" and the other is the hard foam I've cut and stuffed up under the cockpit seating.

floatation3.jpg

floatation2.jpg