Carbon fiber platform

Discussion in 'Materials' started by romeomikehotel, Jan 22, 2020.

  1. romeomikehotel
    Joined: Feb 2019
    Posts: 29
    Likes: 3, Points: 3
    Location: Ft Lauderdale

    romeomikehotel Junior Member

    Hi guys,

    Im hoping to get some info in regards to carbon fiber and what weight of materials are needed to create a stable standing platform.

    I’m looking to build a platform that can replace a Bimini top while also being sturdy enough for two or three adult males to stand on (think T top/ fly bridge).

    I could make it from glass but weight is a concern and I’m hoping CF can be a reasonable replacement.

    How would you guys build this?

    Thanks
     
  2. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    I am a bit puzzled here - you are worried about the weight of this platform / Bimini top if it is made from fibreglass, but you are not worried about the weight / stability implications of 3 adult men standing on this platform (and I presume that it will be fairly high up)?
    Or have I totally misunderstood your post above?
    What size / type of boat will it be built on?
     
  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    I agree. If you spend a lot of money and time, the weight savings are going to be a tiny percentage of the weight of three American adult males.
     
  4. TANSL
    Joined: Sep 2011
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    Location: Spain

    TANSL Senior Member

    For me the matter is very clear, if he saves weight on the structure he can put 4 people, instead of 3, on the platform.
    Stability?, yes but that is another issue.
     
  5. romeomikehotel
    Joined: Feb 2019
    Posts: 29
    Likes: 3, Points: 3
    Location: Ft Lauderdale

    romeomikehotel Junior Member

    The weight of the structure is a concern for the overall design/performance of the boat.

    The three adult males is a reference for a strength requirement.

    When running light, I don’t want extra unnecessary weight... which is why I asked about CF.
    When at the sandbar/cruising I want to be able to stand on top.

    Though none of this info really changes anything in regards to the question and I’m guessing these follow up questions were posited in order to line up the typical “that’s a bad idea, you shouldn’t do that” response I seem to see on this site way more than is necessary.

    As far as whether or not you agree with idea or want to understand why I’m doing it, Im really not interested in opinions here. Just looking for an answer to a question. If you’re unable or unwilling to provide the information, please move on and I can continue looking for information from more helpful sources.

    If anyone happens to actually have the answer to the original question I asked (How many sheets @ what weight CF would be sturdy enough to hold 3 adult men on a 6x8’ platform?) Id really like to hear from you.

    Regards,

    RMH
     
    Jolly Mon likes this.
  6. TANSL
    Joined: Sep 2011
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    Location: Spain

    TANSL Senior Member

    Okay RMH, you're very right, let's get serious. Let's finish with the jokes and we will give answers that are useful for you.
    In the first place, there are times when it is necessary to demonstrate that a ship can support 4 people/m2 from the structural point of view and from the point of view of stability.
    Secondly, to give you a reliable answer, as you are sure you already know, it is not enough to say that you want to make a carbon fiber platform, but that much more data is needed to give you the clear, professional answer you are looking for. Be, therefore, professional in the question.
    Thirdly, it is possible (depending on the dimensions of the platform and many other conditions) that the weight savings that, surely, you will get with the carbon fiber is so small that it does not compensate you to use it.
    Are we on the right track?
    Regards
     
    Last edited: Jan 23, 2020
    bajansailor likes this.
  7. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    It depends on the size and design. Can you post more information? If you are not interested in opinions, a forum is the wrong place to be.
     
    TANSL likes this.

  8. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    Ok, so we have a bimini roof 6' x 8' which has to be capable of supporting 3 men at (say) 80 kgs each - and in a worse case scenario, imagine that is a point load of 240 kgs in the middle of the 6' x 8' panel.
    When you mention that the 3 men is a reference for the strength requirement, will you actually ever have 3 men up there? If not, why does it have to be so strong?
    Just asking - the more info you supply, the better will be the answers that you receive. Folk on here are not being deliberately critical, but at the same time they want to help you.
    You could make a foam sandwich fibreglass sheet 6' x 8' with enough layers of glass to cope with a maximum deflection of (say) 5 mm in the middle of the panel.
    Add some stiffeners underneath and you can reduce the number of layers of glass.
    Add some carbon as well, and reduce a bit more.
    But it rapidly becomes a law of diminishing returns - how far do you want to go to save how much weight, and at how much extra expense?
    There are an infinite number of possible permutations here.
    And don't discount plain ordinary aluminium sheeting - relatively cheap (especially compared to carbon), very light, and it is good material for biminis and roofs.
    The roof on the aft deck on the catamaran in my avatar is 18 SWG (1.5 mm) thick aluminium, yet people can walk on it quite happily (and have done so for the past 20 years).
     
    Rumars and romeomikehotel like this.
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