Sacrificial layer - when do I remove (drying now!)

Discussion in 'Fiberglass and Composite Boat Building' started by omamari, Oct 31, 2015.

  1. omamari
    Joined: Oct 2015
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    omamari New Member

    Hi there,

    Bit of a new person to 'glassing.

    I'm redoing the top part of one of hulls. I've filled, applied two layers of glass with Epoxy.

    I was told to use this 'sacrificial' layer stuff, that leaves a nice impression on top. I've applied this on top of the last layer of wet glass, and fully wet again. Leaving dry edges, so I can tear it off ---- when do I tear it off?

    - when tacky, dry, sold, wet? Really should have thought of this question before I started, thanks for your help. Photo coming.

    Dan
     
    Last edited: Oct 31, 2015
  2. omamari
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    omamari New Member

  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcome to the forum.

    I think you're referring to peel ply, but typically you don't put more epoxy on the peel ply. Your picture looks like peel ply, so wait until it's good and solid, then peel it off. The over coat of epoxy should break up, as you peel it off, making a mess, but should do no real harm. Of course, it's going to be a bit harder to remove the peel ply, with a top coat locking it to the underlying coatings, but you don't have a choice now. All peel ply does is protect the freshly applied coating from environmental contaminants and leave a uniform cross hatch pattern.

    In the future, when in doubt, ask.
     
  4. omamari
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    omamari New Member

    Ah, that's the term he used! Peel ply. Thanks. I am adamant he (fibreglass man) told me to make sure all of the peel ply was wet and was not white anywhere. Ok, I'll leave it overnight and some, and then rip it off when it is all solid. Interesting. And thanks heaps for your quick response!
     
  5. PAR
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    PAR Yacht Designer/Builder

  6. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    There are many different peel plys and how they release from the laminate can vary greatly. Some will bond almost like another layer of glass if you allow the resin to cure, others will pull off easily. The price of the good ones can be high.
     
  7. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    I'm hoping it's a good peel ply, as I hinted at in a previous post, it can be a prick to pull free, if much bleed through has a occurred. The striped stuff often is . . .
     
  8. omamari
    Joined: Oct 2015
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    omamari New Member

    Hey guys, it turned out nicely I think. Peeled off really easy with no mess at all. There a few little convex bubbles/dents which is annoying, but mostly it's fine.

    The corners I had peeled off a bit early, so the resin appears clear.
    The rest I peeled off much later, there the resin appears hazy.

    It has a nice imprint (good for grippy deck) all over and has blended in well with existing edges.

    I don't think it is strong enough, as it has a bit of flex too it [can't be bothered doing another layer, I think it will end up too fat too]. Maybe I'll paint it if I'm feeling extravagant, with, something. I'll put up a photo tonight for your curiosity.

    Thanks again all.
     
  9. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Good to hear it came off neatly. Peel ply grain isn't very good as texture for a deck. It'll fill in with paint pretty easily. Wait a few weeks before deciding if it's still too flexible, the epoxy will continue to cure during this period. Fair, smooth, prime and paint, when you're satisfied.
     

  10. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Bear in mind that epoxy mnust be coated if you use it outdoors. The UV can destroy it.
     
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