Dying Off Laminates at Transom?

Discussion in 'Boatbuilding' started by CatBuilder, Apr 13, 2011.

  1. bntii
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    bntii Senior Member

    Is this where the halves are being joined Cat?

    Typically a ground out and filled void is not considered to be a structural discontinuity as it is fully covered by properly applied glass.

    Particularly if on a joint as shown below where the glass has to be tapered to allow the laminate filling the joint in any case:

    void.jpg

    Void shown in red- it would have been ground out before glass fill is lain down.

    *The above illustration for illustration purposes!*

    Look at the build spec for how to make up the shell halves.
     
  2. hoytedow
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    hoytedow Wood Butcher

    Which scenario are you dealing with?

    I must be off to work now. I will check in this afternoon.:cool:
     

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  3. CatBuilder

    CatBuilder Previous Member

    Yes! That is exactly where the void is. Thanks for the diagram. The little red bit (not the larger orange ones) is precisely where the void is.


    However, I don't have that kind of keel. It's a bit different. There are just a several pieces of biaxial tape holding the keel together.

    So if I grind it out, what do I do after?

    Fill it in with the same triaxial I have on the rest of that laminate? If I do this, this small area will not have the same laminate as the rest of the hull. Is that a problem?

    Or... do I just grind it out, bog it and let the biaxial take care of it?

    Hoyt: I'm dealing with scenario "B" above. Foam is in perfect, square shape, glass is just lifted off a little bit on the edge. It is not as deep in from the edge as you show in the drawing. It only travels in about half an inch from the edge.

    Also, my keel lamination goes like this:

    [​IMG]
     
    Last edited: Apr 14, 2011
  4. hoytedow
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    hoytedow Wood Butcher

    Hello. That small void sounds really miniscule. I don't think with the multiple glass layers you will be adding, that the void will be significant. I would grind it and re-glass and fair the hull before adding the other layers.
     

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  5. bntii
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    bntii Senior Member

    A builder friend used to quip of such problems- "it'll come out in the wash"

    Just lean in on the nose of the disk a second longer & dish it out as you grind/prep for the layups over the joint.

    Take note- the "surrounding area" is the end of this laminate at the joint of the hull... . This joint in the laminate is 1/4" away from the center of the void. This hull joint is a major structural discontinuity in the layup. It is accounted for by the laminate schedule at the joint. This joint reinforcement will very handily cover the ground out 1/2" void.
     
  6. CatBuilder

    CatBuilder Previous Member

    Excellent advice.

    Thank you very much. It's good to have some experienced people to help with little details like this.
     
  7. bntii
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    bntii Senior Member

    Good deal Cat.

    You will rapidly become that experienced person with this build..
     
  8. AndrewK
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    AndrewK Senior Member

    As already pointed out because of the location of the voids and lots of extra joining laminates that are going to cover this, grinding them out is the logical solution.

    But I also want to add that grinding any void no matter where it is located is the best solution. Problem with injecting resin to fill voids is that inside the bubble the surfaces will be glossy so you will never have a proper bond.

    Also your 1150g triax will be only 1.3mm thick, fairing this out is easy.
     
  9. CatBuilder

    CatBuilder Previous Member

    Thanks, Andrew... who I now probably have to buy an entire brewery for when I next visit Australia! ;)

    I did know that injecting resin doesn't work at all since you can't key the inside of the bubble to accept the new resin.

    They are tiny little imperfections, but my #1 fear is delamination, so I will grind them out as I get prepped for the keel laminations.
     
  10. hoytedow
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    hoytedow Wood Butcher

    I knew it wouldn't be a good bond, but it would have lessened the "crush" factor. Being small areas I figured the overall surface bond would more than compensate for it.
     
  11. AndrewK
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    AndrewK Senior Member

    Filling a void with resin is better than leaving as is, but I would never consider doing this if further laminating is to go over the top.
    And while it is tempting to inject voids in areas where there is no further lamination to be done (eg topside) the point I was trying to make is that its not worth trying to take the risk of the delamination spreading for the sake of fairing out a 1.3mm high patch.
     
  12. hoytedow
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    hoytedow Wood Butcher

    I do agree with you. I was exploring a way to not disrupt the integrity of the original glass. Grind out is better and is the way I have gone before.
     
  13. AndrewK
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    AndrewK Senior Member

    Perhaps you can do me a good deal for your first charter, what area will you be operating in?
     

  14. CatBuilder

    CatBuilder Previous Member

    Sending PM...
     
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