Flotation Foam - "unsinkable"

ElBichoMalo · #1 03-30-2009, 02:00 PM

I know new boats under a certain size are required to unsink...Ha...I know they will float, not necessarily upright, but I know a lot of our older boats will probably not. I thought most of you did not add any flotation foam, and I was not planning to. However, the recent NFL player incident off Florida (happens to be local for me) has got me thinking. No doubt would have been 4 dead instead of 3 if their Everglades did not float, albeit turtle shell up.

Are you guys adding flotation? Did these boats have it originally? Stringers? Elsewhere?

Fr. Frank · #2 03-30-2009, 03:01 PM

30 plus year old foam isn't likely to do the job, even if the boat has it. However, IF you're redoing the deck, putting foam between the stringers is a good idea.

My 1974 23' Tsunami, when I had the tank out a few years ago, revealed that it had no foam in the hull, except some under the gunnels. So, having a parishioner who was a VP there, I took my boat over to Pro-Line Boats in Homosassa and they poured in six bags of closed cell foam. I had only to pay the labor costs involved. (They also foamed in my new 110 gal. fuel tank which I bought from them as surplus for $350)

They squirted the foam into these plastic bags, turned the bags this way and that, and then laid them in on the hull outside of the stringers, between the stringers and the hull sides on top of some 1 1/2" PVC pipe pre-drilled for drainage. The foam expanded to fill the bags and mold them to the area they were in. The technician said that the foam they put in amounted to about 1800 lbs of flotation, which would float the boat upside down with the nose out of the water for up to 7 to 10 days of constant immersion before any danger of sinking. Because of the configuration of the Tsunami, and not having any of this foam flotation in the stern, it would probably float hanging stern-down and inverted, between a 40 and 70 degree angle due to the weight of motor.

For a price, he offered to derig my engine and windshield, turn the boat upside down of a frame, and re-foam the gunnels and bow underliner areas with the new foam-in-a-bag. This should, they said, cause the boat to float upright in case of flooding or swamping. Capsizing would still cause the boat to turn turtle, but it could then be easily righted once full of water. The cost would have been about $2,400, most of that labor and rigging costs.

Check with a boat mfg in your area and see if they will offer the foam-in-a-bag installed in your boat if you want this. With boat sales being so bad, they're probably looking for ways to provide services and make money.

wtenglish · #3 04-10-2009, 11:22 PM

I'm just starting a rebuild and plan on installing foam into any open void I can for structural, flotation and insulation purposes. Caymanboy hooked me up with a good place to purchase it. Check out my post for the website link if interested.

FishStretcher · #4 05-10-2011, 11:14 PM

I looked at a few 20' Master angler repair jobs and some have some boxed stringer foam and modest amounts of foam between the stringers.

Not sure if that is original. The stock deck height seems low enough that it might be difficult to get enough foam in there to float 2000 lb of boat and motor.

I am about to foam in the cavity where my 45 gallon tank was- which comes to a measured (almost) 8 cubic feet, which probably gets me a net of 430lbs of flotation after foam weight, assuming a net of 54 lb/cubic foot or about 1 lb/gallon of foam weight. Not sure where I can find another 1000 lb of flotation volume below deck. I guess I can look under the cap. The forward fishbox is good for 3 cubic feet of removable foam, or maybe double that of "chisel removable" foam, but with tanks where the head was, there is precious little room for stowing crap, and the fishbox is a nice thing to keep.

Anyone know the buoyancy of a 1975 20 foot Master Angler as new?

Quote:

30 plus year old foam isn't likely to do the job, even if the boat has it. However, IF you're redoing the deck, putting foam between the stringers is a good idea.

My 1974 23' Tsunami, when I had the tank out a few years ago, revealed that it had no foam in the hull, except some under the gunnels. So, having a parishioner who was a VP there, I took my boat over to Pro-Line Boats in Homosassa and they poured in six bags of closed cell foam. I had only to pay the labor costs involved. (They also foamed in my new 110 gal. fuel tank which I bought from them as surplus for $350)

They squirted the foam into these plastic bags, turned the bags this way and that, and then laid them in on the hull outside of the stringers, between the stringers and the hull sides on top of some 1 1/2" PVC pipe pre-drilled for drainage. The foam expanded to fill the bags and mold them to the area they were in. The technician said that the foam they put in amounted to about 1800 lbs of flotation, which would float the boat upside down with the nose out of the water for up to 7 to 10 days of constant immersion before any danger of sinking. Because of the configuration of the Tsunami, and not having any of this foam flotation in the stern, it would probably float hanging stern-down and inverted, between a 40 and 70 degree angle due to the weight of motor.

For a price, he offered to derig my engine and windshield, turn the boat upside down of a frame, and re-foam the gunnels and bow underliner areas with the new foam-in-a-bag. This should, they said, cause the boat to float upright in case of flooding or swamping. Capsizing would still cause the boat to turn turtle, but it could then be easily righted once full of water. The cost would have been about $2,400, most of that labor and rigging costs.

Check with a boat mfg in your area and see if they will offer the foam-in-a-bag installed in your boat if you want this. With boat sales being so bad, they're probably looking for ways to provide services and make money.