fiberglass hull thickness

Discussion in 'Boat Design' started by Gianf1041, Dec 18, 2019.

  1. Gianf1041
    Joined: Sep 2018
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    Location: italy

    Gianf1041 Junior Member

    For the bottom up to the waterline which sequence of fabrics I recommend you apply starting from the gel coat to laminate the immersed part of the hull, I calculated a thickness of 18 mm animated with 7 mm foam core.
     
  2. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    That is intuitively too thick. How are you arriving at such high thickness and who makes a 7mm core?
     
  3. Gianf1041
    Joined: Sep 2018
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    Location: italy

    Gianf1041 Junior Member

    Traditional simplified rules .......... "The elements of boat's strength" - David Gerr - ..... a boat scantling number is identified ....... simple formulas for immediate reading, example : the calculation of the average thickness of the hull plating, ........ 15% less than the average thickness in the upper part, 15% more than in the sides in the immersed part .......... ... formula: t = (3,28 x Loa) 0,5 + (Boa x 3,28 x 1,58) ....... t = average thickness in monolithic fiberglass. ?????
     
  4. fallguy
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    fallguy Senior Member

    You are proposing more glass than core!!!

    No way is that right.
     
  5. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    You can't start a design by determining a laminate schedule. Otherwise, there is no justification for any of the dimensions. The laminate is not the basic starting point, but rather one of the finishing points.
     
    bajansailor and fallguy like this.
  6. Gianf1041
    Joined: Sep 2018
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    Location: italy

    Gianf1041 Junior Member

    Sorry but, ...... I probably don't explain well with the English language; with the proposed formula I only calculate the average thickness of the hull regardless of the type of laminate .......... my idea is to evaluate whether it is more convenient to think about the bottom of the animated hull or just grp / resin fabric. I hope I have translated my idea correctly.
     
  7. Gianf1041
    Joined: Sep 2018
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    Location: italy

    Gianf1041 Junior Member

    It is certainly not the starting point but it is one of the points for calculating the weight of the hull ........, if the hull is monolithic or with a soul.
    animated laminate ............ the weights are different. ??
     

  8. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    You can't calculate the total weight of the boat starting by the lamination. The lamination will be designed based on loads. The static loads will be determined by the interior appurtenances, machinery, tankage, etc. The dynamic loads are determined largely by speed and area of operation. Further, framing or lack of it also has a huge impact on the laminate schedule. It is not a language problem, but a method problem. Start at the beginning: What and where are you using the boat for?
     
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