composites

Discussion in 'Boat Yard Basics' started by jms, May 4, 2012.

  1. jms

    jms don't let common sense get in your way

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    composites:

    these are definatley the best choice when replacing wood coring - the composites will last indefinatley,will not rot.
    problem is,they will not hold a screw,nida core is the absolute worst - it's a honeycomb material
    this is an example of the incorrect technique for mounting equipment to a composite cored surface.this "t" top was mounted on the deck,using "toggle" style bolts - my experience has been,these fail - seen these fail numerous times.there's one true way to mount equipment onto a composite cored surface - thru bolting and sleeving.in certain applications,this isn't possible - t top mounting is an example-these applications require the core surface be removed and the area where the fasteners be filled with epoxy mixed with the appropriate thickener.this will hold a screw,also holds threaded machine screws,when the holes are the correct size.
    remember this,when you're mounting grab bars,seats and consoles,on a composite cored deck...

    [​IMG]
     
  2. Izzy11

    Izzy11 Backwater boy for life

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    Great advise ! .... I've got a minor in nidacore LOL after rebuilding a few boats.... You ABSOLUTELY must fill ALL edges and holes with fiberglass filler of some sort and double rap your rails and edges with glass ! I even pre cut my rod holder holes and hollow out the inner circle and fill it with fiberglass filler !
    You have to because even though core will not rot it can still allow water to intrude !
     

  3. Izzy11

    Izzy11 Backwater boy for life

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    I also wanna give a pointer .... I use a big syringe for the fiberglass filler and I drill the end hole out to be a little bigger and use it for my filler to get into those hard to reach areas . So wherever you are going to put a screw you just pre drill your screw holes. Fill them with filler, then re drill your screw holes in the dry filler, and install your rod holders or whatever .
     
  4. jms

    jms don't let common sense get in your way

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    that's imperative for nida core - water will intrude it - nida core is a honeycomb,as you're well aware of,it's hollow,uses plastic as a stiffener - terrible stuff,i do not use nida core for anything....

    penske board,coosa,these will not absorb water...
     
  5. Izzy11

    Izzy11 Backwater boy for life

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    So I got a call from a forum member about nidacore. I wanted to explain so nobody waist there time that you do not have to fill all edges... Such as where the core meets the hull. So if you are putting in a deck and you go to install it you only need to glass it in from above and below.
    Also , from what I've been told nidacore is more lite than dyvinicel when finished. It also cost less.
    I do believe it is the most difficult to finish properly but it does work great. Just takes twice the amount of time to work with ::)...

    If you read this I would like to hear what you use for composite material and why... Thanks
     
  6. jms

    jms don't let common sense get in your way

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    there's a big reason nidacore is much cheaper than a dense foam composite,such as divinycell - it's called "quality"

    this is nida core - it's basically a hollow honey comb composite,made from recycled milk jugs,with a light scrim backing

    [​IMG]

    this is what it looks like with the scrim backing removed

    [​IMG]

    this is a side view of the same product

    [​IMG]

    not much there - it's hollow between the honey combs,these areas,they can and will become filled with water,from improper sealing,and improper fiberglassing techniques used.this design does have a pretty good compression rating.think this would hold a screw ? this type of core relies on a fiberglass skin,to provide rigidity - kind of like an "I" beam...

    this is a structual composite - penske board,a dense foam composite,with a glass fiber in it.has excellent compression resistance,and it's dense,not hollow,it will absorb no water,half the weight of plywood,weighs slightly more than nidacore.this is a product i use and endorse.

    [​IMG]

    side view

    [​IMG]

    this is an excellent choice for stringers,bulkheads,decks and transoms


    big difference huh ?
     
  7. Recidivists

    Recidivists Looking towards the weekend!

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    I'm gonna say that nidacore would be the least desirable plastic or composite material I would want to have on my boat. If I were to have thru bolts or any type of penetration, I would prefer a solid material. Is it light and does it cost less? Yes. Do I condemn any one for using it? No.
     
  8. Izzy11

    Izzy11 Backwater boy for life

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    From what I've heard.... Nidacore is actually the least water intrusive if done correctly.   And this comes from a guy who sells it all and knows I would buy anyone of them if he told me to.

    Now... I'm not in anyway trying to cause a feud ! I really would like to know which one is the best OVERALL.

    Lightest, strongest, cheapest , and easiest to work with ???
     
  9. jms

    jms don't let common sense get in your way

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    no fued here - just discussing products...

    water intusion - a dense composite foam,like coosa board,penske board - these products will not absorb water,these products have no voids to allow water to collect - think about the hollow honeycomb pattern of that nida core,think of water migrating in the hollow voids - now throw freezing temps,in the mix...sounds like a recipe for trouble...

    the lightest,strongest,easiest composite to work with,in my opinion is either penske board,or coosa board.
     
  10. Izzy11

    Izzy11 Backwater boy for life

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    Great info ! So with these core materials you can just put screws or rod holders directly into it with no prep ? And it is half the weigh of wood ? What's the cost ?
    What do you think of divinycell ?
     
  11. cutrunner

    cutrunner Cert. Yamaha technician

    What do you guys think of pvc board, minus the fact that its heavy as he!!?
     
  12. jms

    jms don't let common sense get in your way

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    no composites hold screws well - thru bolting and sleeving -
    perhaps you missed this "problem is,they will not hold a screw,nida core is the absolute worst - it's a honeycomb material
    this is an example of the incorrect technique for mounting equipment to a composite cored surface.this "t" top was mounted on the deck,using "toggle" style bolts - my experience has been,these fail - seen these fail numerous times.there's one true way to mount equipment onto a composite cored surface - thru bolting and sleeving.in certain applications,this isn't possible - t top mounting is an example-these applications require the core surface be removed and the area where the fasteners be filled with epoxy mixed with the appropriate thickener.this will hold a screw,also holds threaded machine screws,when the holes are the correct size.
    remember this,when you're mounting grab bars,seats and consoles,on a composite cored deck..."

    i typed that,in the original post i made...

    divinycell is another excellent structual product - there's a few grades of it,depending on application...
     
  13. jms

    jms don't let common sense get in your way

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    trimming a house ?

    never used that stuff,never would either...
     
  14. Izzy11

    Izzy11 Backwater boy for life

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    Kreepa.... My bad.. I didn't miss it, I just was trying to get the exact info you gave in the last post. Nidacore is the cheapest and works well in my opinion though it does take more to work with it correctly. The other materials cost double and triple what nidacore does and nidacore is lighter.
    My technique is exactly what you suggested....

    Pre fill your holes with filler then re drill your screw hole and install. If possible drill all the way through so that whatever water creeps in can have somewhere to go. Also... I like to grind the edges down and double glass them and fill the edges with filler......

    My response about the PVC is this..... You can use whatever you want if it's strong enough. And people do ! Honey comb is PVC .
     
  15. jms

    jms don't let common sense get in your way

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    price alone,will not provide a true comparison of value - remember that...


    when drilling out and filling the hole,to provide a mounting area for fasteners,it's best to use an epxoy based product - polyester based products are brittle,and will break apart - epoxy based resins are a much stronger product,along with being waterproof,unlike pourous polyester based resins...

    people use alot of different products on their boats - i often see examples of this - doesn't make it right or wrong - i stick with products i know are suitable for the application...
     
  16. Brett

    Brett > PRO STAFF <

    At the moment this thread has been viewed 223 times, 15 of which are mine.
    Every time one of you adds to the thread, I have to read it. Thanks.
    All useful information regarding materials I have little or no experience with.
    Very useful guys...keep it up.  :cool:
     
  17. Izzy11

    Izzy11 Backwater boy for life

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    I hear ya.

    I've seen great work whether it be with wood or composites.

    Obviously if you're using cores then that beats wood all day long "but heck" ,... There are wood boats out there that have withstood the test of time when treated with respect.

    I believe that you and I are both correct in different ways ...

    Yes ... Nidacore will not rot but it is the most water intrusive if not used properly. It is however the most lite and the least expensive of the core materials out there.

    Coosa and divinycell "may not be spelled correct", they are stronger and MUCH MUCH easier to work with. They are also not as water intrusive.

    But they cost much more and are heavier.

    I have no doubt that you have much more experience than I and that's all right with me. But at least I'm learning ;D
    I hope we can talk in the future when I need help. I still have a lot to learn . One thing for sure.... Ive got the bug !

    Thanks
     
  18. jms

    jms don't let common sense get in your way

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    weight difference:

    when working with a core material like nida core,you're gonna use more glass and resin - it's how it is...adding these adds weight - every gallon of polyester resin,or vinylester resin is 10lbs,plus the weight of the cloth/matt...

    the weight difference between all composites is minimal - not really a factor...

    people will have differing opinions,but,experience tells me what's a better product for differing applications...
     
  19. jms

    jms don't let common sense get in your way

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    nothing wrong with wood coring - the problem with wood coring is,failure to seal the wood - using a polyester based resin on wood,that's not the best choice,due to polyester being pourous...
    the biggest problem with wood is installing equipment and not properly sealing the holes - properly sealed,it's not a factor

    yep,there's alot of old wooden boats out there - but,let's be serious,technology evolves - if it didn't,we'd still have wooden boats - products evolve and technology changes - composites - i've stopped using any kind of wood on repairs - i use strictly composites - mostly penske board and coosa,in core repalcement applications...

    bottom line is,there's allways more than one way to skin a cat...
     
  20. DuckNut

    DuckNut Brandon, FL

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    Kreepa- since you have the best avenue to actual prices put together a workup.

    Compare the cost to build a front and rear deck with a hatch in each and just assume that you will be using 1/2 sheet for each. And illustrate a couple of the types you like and nida.

    Include the weight and price of each raw material and then how much resin/cloth to make safe. Include the amount of time a non-professional might take to make the product but assume labor is free.

    I think some might find out just how inexpensive and light nida really is. ;)
     
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