which one goes on first.

Discussion in 'Fiberglass and Composite Boat Building' started by Tungsten, Jun 3, 2012.

  1. Tungsten
    Joined: Nov 2011
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    Tungsten Senior Member

    i'm building a small boat, the floor is 48" wide and 130" long the ends taper a little to creat some rocker.


    here is what i have , i can't return any of it so i want to use it.

    12 oz 45 45
    12 oz 0 90
    18 oz wovin roving.

    this will be going on Corecell 1/2" M80 foam

    my question does it make any difference which goes down first?i think the 18oz WR will go last.so 45 45 first or 0 90?

    there will be 2 benches in the boat tabbed to the sides and the floor.

    thanks.
     
  2. tunnels

    tunnels Previous Member

    Like all things yes it makes a differance what goes where and how you use it !!, change things round changes the way things will work !!
    What resin you going to use ??
    Pictures ,drawings, sketch, anything ??
    a little more info could make a big differance and be more helpfull !!:confused:
     
  3. Tungsten
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    Tungsten Senior Member

    i guess my question wasn't clear,or its just a stupid question.won't be my first nor last .

    so lets try another,2 layers of 45 45 or 2 layers, one 45 45 one 0 90.which one will be stiffer?
     
  4. Herman
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    Herman Senior Member

    Depends on the direction you will load it.

    2x biax45 will create more torsional stiffness, one biax45 and one biax0/90 will create a more isotropic laminate.

    To be very honest the differences are not that much, and I would use what gives the best aestetics. Save some biax45 for the tabbing, it works wonders.

    Do not think too difficult, just do it, and you will very probably be happy with the result.
     
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  5. tunnels

    tunnels Previous Member

    You got it and couldnt do it any better !! :D
     
  6. rawleyjerel@yah
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    rawleyjerel@yah Junior Member

    i would alternate one +/-45 one 0/90 think of it as a basket weave. if you use the woven roven in such a small boat i would bury it in between the other layers but i personally wouldnt use it in such a small boat all it would do is add weight not strength,overkill if youd like.also it would cause a lumpy uneven look to thr inside of your hull.woven roven is best designed for use with a chop gun as the chop burys it enough to not cause print thru to the outside of your part visible thru the gelcoat.
     
  7. Tungsten
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    Tungsten Senior Member

    Thanks all,ya i was on the fence about the WR.Keeping the weight down is what i'm after.
    i have some peelply now so i'll do another test,i'll try 3 layers maybe 2 45's and a 0 90 and see how it compares to my other test piece with the WR in it.

    its simple questions like this that help a newbie such as myself sleep at night knowing i'm on the right track.

    cheers..
     
  8. tunnels

    tunnels Previous Member

    what are you trying to make ?? what are you trying to do ??:?:
     
  9. Tungsten
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    Tungsten Senior Member

    small pointless S&G flat bottom skiff,2 person boat for floating calm rivers.
    epoxy,1/2"foam floor,1/4"meranti sides.trying to stay under 130lbs so i can load it on my roof rack.
    length 12-13' width at floor 48" beam of 65-70" side height of 22" at the oar locks tapering down to 16" ish at each end to keep sheer line straight to make it sit flat on my roof rack.

    foam floor will have 3 layers of 12oz glass on bottom maybe 2 on the inside to keep it light.meranti sides 6oz glass both sides.bow and stern panal probably foam with same glass.i have some sapele wood for gunnels say 1 1/4"x3/4, benches will be 1/2"foam again but with less glass.tabbed to sides and floor with fillets and 45 glass.

    i think that covers it.
     
  10. sabahcat
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    sabahcat Senior Member

    Using foam for weight saving and then uses rovings ? <shudders>
     
  11. tunnels

    tunnels Previous Member

    I know what you mean and dosent really make sense !:!:
     
  12. Tungsten
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    Tungsten Senior Member

    hint taken,
     
  13. Herman
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    Herman Senior Member

    Multiaxials exposed on the inside is not the best idea either. With relative low effort (read: some small abuse, like throwing in the mast, some oars, etc) fiber might break out. with WR this is not an issue.

    When designing for stiffness, multiaxials are the way to go in this case, but a bit more resilience is expected from WR, as it is a crimped fabric.
     
  14. sabahcat
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    sabahcat Senior Member

    In all honesty I dont know why you wouldn't just stick with the 6 mm ply like you have in the sides, forget the foam.

    I had an 8ft flatty that I did like this covered in 5oz cloth and with 50mm pvc tube as a cap around the gunwale.
    No glass at all on the inside.
    Was used and abused daily and gave me several years of trouble free service.
     

  15. Herman
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    Herman Senior Member

    I think this is a "use what you have" issue. Building boats from scraps is always good. (at least better then making other stuff)
     
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