Oneoff reinforcement unwanted steps

Discussion in 'Fiberglass and Composite Boat Building' started by jiggerpro, Jun 13, 2008.

  1. jiggerpro
    Joined: Sep 2007
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    Location: spain

    jiggerpro Senior Member

    Dear boatbuilding interested colleagues, when building a oneoff (no female molds here) , for example our typical CC , please imagine you have completed the Corecell shape and are going to glass the outside, if as normal the "V" part of the hull has a thicker laminate layout than the sides (to have a better impact resistance) and if the sides reinforcement have to be overlapped by the reinforcement of the "V" part of the hull at the chines and slightly upwards, how is the problem of the quite big unwanted fiberglass step that will inevitable will develop on the sides near the chines is solved?

    Is it there a better way than just adding putty to the thickness of the step created all along the surface of the sides of the boat??

    I have thought to extend the fiberglass of the "V" part of the hull slightly over and up to the sides to give some additional strength to the "V to sides corner" but then a quite big step will be created that cant be removed or we will remove the strenght with the removal.

    Should it be made by layering the fiberglass in a way that the step is not so steep by cutting the cloth layers smaller and smaller so the step is not so steep and then putty it??

    Thank you all for your altruism and expert advise
     
  2. Herman
    Joined: Oct 2004
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    Herman Senior Member

    How about glassing from one side, over the keel, to the chine on the other side. Repeat this for the other side, and now your sides have 1 later of glass, and the bottom has 2 layers. No overlaps are made this way.

    Another way is to predict where the overlaps are, and routing away the corecell in that area slightly (say 1mm). This requires accurate glass laying.
     
  3. jiggerpro
    Joined: Sep 2007
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    jiggerpro Senior Member

    Hi Herman; Thank you for your input, but I thought, that the drapability of the fiberglass would not allow that ( unless mat is used which will not be) particularly if the hull is quite curvaceous like for example those found in yellowfin 34´s.
    In order to reduce weight and get a decent fiberglass to resin ratio I am thinking of using knitted glass cloth and belived that it would not allow what you propose which certainly sounds like the best way because there are less fiberglass joints and therefore the best possible integrity ..... you are a friend.
     
  4. the1much
    Joined: Jul 2007
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    Location: maine

    the1much hippie dreams

    you should still be able to do it,,even heavy glass can be put on upside down,,, you just need to watch out for too much resin wieghing it down,,,but since your going so far up the other side,,it will make it easier,,,just need to wet out the top part near the chine to hold it there,,,,or use tape,,,,then go back to keel and go around that.,,,,,what hermon is suggesting should work without alot of worring bout ya glass staying.
     
  5. Herman
    Joined: Oct 2004
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    Herman Senior Member

    I was even talking about the boat still being up-side-down.

    I guess the TS is worrying about bias-shifting the glass, when applying. This should not be a problem. First of all, carefull measuring should do the trick, rolling the right amount of glass onto a spare cardboard tube (keep some overlength) then roll into a wet layer of epoxy or polyester on the boat. Cut exactly to length on the boat. The scissors will get resin on them, so clean them well after the job.

    When using multiaxials, try and avoid loosely stiched +/-45 biax, as this will shift a lot. Stabilised 45 biax will work though (there is a small amount of 0 and 90 threads in them, which keep the mat stable). If you really need to use them, do not expect a fixed width, so the trick with recessing the foam will not work for that layer. (it is usually only the first layer that receives this treatment, and only if the first layer is a heavy one, and the second is light. If there are 3 or more layers, butt-joining is possible.)

    0/90, triax and quadrax are OK, handling wise. They are far more stable.
     
  6. jiggerpro
    Joined: Sep 2007
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    jiggerpro Senior Member

    I wish I had mega collaborative and knowledgeable people like you Mr Herman and Mr Onemuch around to give a hand ( me paying naturally) when the moment arrives but there is the big pond between us, I have made windsurf boards for myself and others since 25 years ago and have been "studying" ( only theoretically ) the subject of boat building since that windsurf board era. The time of truth is getting closer since my boat buiding premises are being built at the time as a part of an industrial building which is under construction right now. There are no boatbuilders at all in the Canary Islands where I live or at least no "decent" ones, there is only one small skiff builder so maybe, with some luck and hard work I will be the only one here in the Canary islands. Spain ( in the mainland) has seen a few succesful entrepreneurs succeed in boatbuilding despite the fact that their designs in my opinion are quite too conservative, me, much more liking the american more courageous approach to the design and philosophy of the boats made there. Here is what is being made right now ( the premises) and what I plan to build (the boat), I wish I had some people like you around to be contracted as technical advisors, but much I am afraid I will have to be happy with only your virtual presence and friendship but who knows our world is getting smaller and smaller, lets just hope that the developing oil crisis or those greencomunists that abound do not kill so many interesting boating projects and industrys.
     

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  7. Herman
    Joined: Oct 2004
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    Herman Senior Member

    Great project, you really make things happening out there.

    Do not worry about the laminating job. Once you get at it, you will see that it is not that difficult to do. Make some test panels (with some overlaps) and see what is the easiest solution for you.

    Make photos of what you like and what you do not like, and post them here. We are all out here to help you.
     
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