Floatation

Discussion in 'Boat Design' started by KenO, Jun 12, 2018.

  1. KenO
    Joined: Jun 2018
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    Location: Alabama

    KenO New Member

    I have a 22' Starcraft, Deep V, Center Console, Aluminum, and Riveted. Boat has been on a fresh water lake but I will use it in salt water. In process of restoration. Removed everything including the floor and the foam. The foam was wet on top and had trapped water underneath. I cannot take the chance of trapping salt water. I did have the outside bottom epoxied and painted and put two coats of epoxy on the inside. I do not want to use expanding foam under the deck so what should I use?...Pool Noodles? Life Jackets, a couple of Beach Rollers?
     
  2. Mr Efficiency
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    Mr Efficiency Senior Member

    Was there corrosion on the inside bottom, where water had got between the foam and the hull ? Was the hull inside painted before the foam was installed, originally ? A good paint job takes away a lot of the terrors of poultice corrosion, which can bedevil alloy in contact with foam. Ideally you don't want foam in an alloy boat, that can't be removed reasonably easily, because if it is a permanent fixture, welding repairs become a fire risk. Your options appear to be polystyrene, best coated with a latex paint, or flexible polyethylene foam, which is a bit expensive.
     
  3. KenO
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    KenO New Member

    Thank you, there was no paint on the inside bottom. There was no corrosion I guess since the boat was only in fresh water. I will check out the two foam materials that you suggested. I believe pool noodles are made from polyethylene but will find this material in a more solid form as compaired to a pool noodle. Thank you.
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    Don't laugh, but plastic drink bottles are the choice of some, as buoyancy, but of course even when carefully packed, still leave a fair bit of the volume not doing the job. Better than nothing though, I cringe when I hear stories of boats that sank like a stone, and only an epirb and a prompt rescue effort saved the occupants.
     
  5. BlueBell
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    BlueBell Ahhhhh...

    Sounds like a happy enough ending to me.
     
  6. Ike
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    Ike Senior Member

    OR, you good use polystyrene insulation foam, wrap it in vinyl plastic and seal it up so water can't get to it. Home Depot, Lowes, and other hardware outlets sell Polystyrene Insulation foam in sheets, 2" thick by 2 ft by 8 feet. This is not styrofoam. Styrofoam is a brand name, usually white and has much bigger foam bubbles and is easily damaged. Polystyrene insulation foam is generally pink, or blue depending on brand. It's relatively cheap, has much smaller cells and is 2 lb density (1 cubic foot weighs two pounds) Cut it to the size and shape you need, Get some heavy duty vinyl plastic (probably at the same place) Wrap the foam and seal it with a good packing tape. see here how I did this on my SeaRay.
    Boat Building Projects | 1972 Sea Ray 190 Rebuild http://newboatbuilders.com/pages/SeaRay190.html
    Ten years now and no problems. The problems with polystyrene? Polystyrene is affected by most petroleum products and a lot of cleaners. So you have to protect it. The vinyl does double duty. It keeps the water out as well as any spilled oils, gas , bilge cleaners and so on. It is 2 lb density foam so calculating how much is needed is simple. But in this case I don't think you need to do that. Just fill the space where the blown foam was. Pool noodles (polyurethylene foam) will work but cost you a lot more. Bottles are good as long as they are sealed so water can't get into them, but it takes a lot of bottles. There are other solutions, but in many years of advising boat builders on how to install foam flotation this is the best and least costly solution.
     
  7. KenO
    Joined: Jun 2018
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    KenO New Member

    This sounds great and I will start on out this week. Thank you!
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

    I wonder whether sound kind of device to weld Ike's plastic sheet sealed watertight, might be a good idea, certainly fuel can make an awful mess of PS foam, and tape might let go in places.
     
  9. Ike
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    Ike Senior Member

    I had the same thoughts. So what I did was make sure the seams were double overlapped and always on top. By double overlapped I mean folded back over themselves.
     
  10. JSL
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    JSL Senior Member

    I hope I am wrong but just in case..!
    You may want to check if you have to comply with any regulations/standards (USCG, ABYC, etc) regarding the method (foam, air bottles, etc) and materials (urethane, Styrofoam, etc). For your own use you may be okay but if you sell the boat you may be responsible for any deviances or non-compliance.
    Air chambers are not compliant and if the boat is fitted with gasoline, the foam must be 'gasoline proof'' (ABYC H-8)
     
  11. Ike
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    Ike Senior Member

    Actually he doesn't have to comply with Federal Flotation regulations at all. The regulations ( Title 33 CR 181. 201 - 183.205) only apply to monohull boats under 20 feet in length. This boat is 22 feet. The manufacturer voluntarily choose to follow the ABYC standard H-8 which also only applies to boats 20 feet or less, but manufacturers can choose to put flotation in larger boats if they wish to. Both the regulations and the ABYC standard do not specify what materials can be used. It is a performance standard. That is, the boat must float in a certain attitude when swamped. If equipped for level (or upright) flotation then there are limits on how far it can heel when load with an amount of weight to simulate passengers and gear, and how far the bow or stern can be submerged. Air chambers are allowed if the boat can meet the standard with the two largest air chambers flooded.
    8.6.3.1.2
    For boats requiring Level Flotation, per TABLE 1, in each boat to be tested, water must flood the two largest non-integral air chambers.
    The water level inside these two chambers must be allowed to change freely so that it is even with the swamped attitude of the boat

    Over years of testing boats for compliance with the federal regulations I have seen everything from air chambers to beer cans, plastic bottles, and ping pong balls. If it works it's good.
     
  12. JSL
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    JSL Senior Member

    Thanks Ike
    Oops, forgot the 20' reference-
     

  13. Ike
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    Ike Senior Member

    oh, and just to make it more confusing, especially to the public, the flotation regs only apply to boat manufacturers/builders. No requirement for boat owners to keep it in compliance ( I'm only talking flotation now. Some of the regulations do apply to boat owners.) Of course then you get in a whole other discussion about resale, liability, insurance and surveys and so on. So it's best to just restore the flotation.
     
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