kevlar in boatbuilding

Discussion in 'Materials' started by wadeed, Jul 14, 2012.

  1. wadeed
    Joined: Sep 2006
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    Location: egypt

    wadeed Junior Member

    worked with csm and wr but would like to use kevlar and ve
    can any one tell me if can lay kevlar material on top of each other or need bedding layer
    also can use hybrid kevlar and tawaron or kevlar only
    thnks:cool:
     
  2. tunnels

    tunnels Previous Member

    From my past exsperiances have always used ve resin and kevlar with a 225 csm as a resin glass filler bedding only !! but other people my be able to advise you other wise .:idea:
    Remember not all ve resins are born equal so be carefull and do your home work and speak with the resin supplyer and check what is needed !!.
    :)
     
  3. wadeed
    Joined: Sep 2006
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    Location: egypt

    wadeed Junior Member

    you use csm alternate between kevlar layers or only as first layer after gelcoat as surface layer:confused:
     
  4. tunnels

    tunnels Previous Member

    Its was found that If you lay flat layers one on top of the other Any of the layers including woven roving theres a resin only very tin layer between !! so thats why theres a 225 gram or what ever on one side so it mixes ,sandwichs and beds with the resin layer and glass reinforces it!!!
    Resin alone is brittle over time with continual flexing it will gradually crack and break up and crumble but with the little bit of glass added its dosent happen , make sense??
    We all have this mind fix that csm soaks lots resin !!,one no glass materials soaks resin it wets out and resin is taken up by the bundles of fibres through capilary action ,so if you use fast brews of resin the wetout is hampered and gel takes place before its done it job 100% so your fancy laminate might not be as strong as you thing it is !! , two, csm is there for a purpose to re-enforce the resin rich layers between layers materials:p.
    The effect of fibre print through is cosmetic and one day soon some one is going to try and convice us all its killing speed or the opposite its benificial to increase speed or what ever .I am suprised there hasnt been a multi million dollar grant to some obsure brain stormer no one has ever heard of to do a life time study on that very subject !!!.
     
  5. midnitmike
    Joined: Apr 2012
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    Location: Haines and Juneau

    midnitmike Senior Member

    My personal experience tells me that laying up two woven materials side by side does not work well. An impact will separate these layers while alternate layers of csm and woven material at the same site will remain intact.

    Although Kevlar may provide you with a unique selling point for your customers It's so much harder to work with before, during, and after the lay-up that increased labor costs should be expected. Unless you have some specific need for a Kevlar laminate and the customer is willing to pay the additional costs I'd stay away from it.

    MM
     
  6. wadeed
    Joined: Sep 2006
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    Location: egypt

    wadeed Junior Member

    any idea on s glass and tawaron in boatbuilding instead of kevlar:confused:
     
  7. tunnels

    tunnels Previous Member

    Tawaron i have not seen or used but only read about and sounds the same as kevlar or very simular !!

    Personally i would not use it with glass!!.
    Why do you keep pushing these odd ball materials ?? what are you making ??
    Long time ago was a big drift to Kevlar and then kevlar and glass combination fabrics in all kinds of pretty weaves and patterns now i dont know of anyone that uses it !!.
    So tawaron i imagion could be the same , i read its used for making rope and there it should stay .
    For building if you start with glass you should carry on with glass and dont mix dissimular materials will only lead to a disaster furthere down the track i reckon .

    I am in agreeance with this from midnitmike
    My personal experience tells me that laying up two woven materials side by side does not work well. An impact will separate these layers while alternate layers of csm and woven material at the same site will remain intact

    The csm is there to grass reinforce the resin layer between the two materials . when you worked with glass for long time you know instinctivley what works ,what should work ,and have a gut feeling about what wont work !! :)
     
  8. Herman
    Joined: Oct 2004
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    Location: The Netherlands

    Herman Senior Member

    Twaron = Kevlar. just different manufacturers. The material name is Aramide.

    Used extensively in ropes and cables. Optical cables use a lot of aramide, for its higher stiffness than the glass fiber (so the aramide bears the load, and the glass is being kept intact), and it is flexible, without breaking.

    Another very good application is armoured plating. Both in hard sheets, and in loose curtains. (which works really well). For this application there are different variations of aramide.

    In boats it is grossly limited to damage control. If an impact occurs, it keeps the debris together, potentially saving the boat.
    I always advise it to use mixed 50/50 with glass in the same fabric, as to reduce the risk of delamination.
     
  9. ClarkT
    Joined: Jun 2003
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    Location: New Orleans

    ClarkT Senior Member

    S-Glass + Twaron

    Twaron is just a different aramid with nearly identical properties to Kevlar, but a different patent.

    I agree with everything said about bonding a kevlar ply to kevlar ply. Unless you are using an epoxy, a layer of CSM between the two is essential for adequate (not excellent) bonding.

    S-Glass is stronger than E-Glass and MUCH tougher. I can not emphasis this enough. If the mission is toughness vs. weight while maintaining stiffness and some degree of economy, you'd be wise to dispense with the aramid entirely and simply look to S-Glass.
     

  10. Ajg2199
    Joined: Aug 2022
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    Location: USA

    Ajg2199 Junior Member

    Does this not apply to stitched fabrics and/or epoxy laminates?
    It would explain the prevalence of 1708. But then wouldn’t there also be woven fabrics with CSM stitched on?
     
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