General Fiberglassing Questions

Discussion in 'Materials' started by ElHurrecan, Apr 8, 2018.

  1. ElHurrecan
    Joined: May 2017
    Posts: 5
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    Location: USA

    ElHurrecan Junior Member

    I have a thread going where I'm restoring the floor and transom on an old "Hurrecan" skiff (If you're interested see my post history). I'm going with epoxy and from advice from another thread at iboats I will be ordering 1700 no-mat bi axial for everything.

    A few questions

    1. How should the final product look?

    A buddy is doing a restoration on an old Whaler. He used 1708-biaxial (his had mat) with epoxy and his finished product looks as follows. Should the mat be "white" with clear spots or does that indicate the resin did not completely work it's way into the mat? His application technique was to wet the glass base, lay the mat, then brush resin into the mat. He used a finroller to work out bubbles.

    [​IMG] upload_2018-4-8_15-56-55.gif
    [​IMG] upload_2018-4-8_15-56-55.gif
    [​IMG] upload_2018-4-8_15-56-55.gif
    [​IMG] upload_2018-4-8_15-56-55.gif

    2. Application technique

    Most of the videos I see online are for either small repairs or polyester resin. I see the resin applied with a roller. Do you recommend a roller over a brush? I will be doing flat areas (floor and transom).

    3. Overlapping the 1700 mat

    My boat is 55" wide. Given that the mat is sold in 36" widths I have to overlap. Should the mat overlap? This will obviously create a hump. Is the following a good plan to lay the mat? Essentially I tab in the floors (going a few inches onto the floor and up the hull, lay a piece of mat down the center, then overlap the center map and tabbing with a third layer.

    [​IMG] upload_2018-4-8_15-56-55.gif
    (Full Res - https://www.iboats.com/sites/default...?itok=UqwXZaUs)
    4. Finishing

    Given that I'm using the 1700 mat the "weave" pattern may show through. I also have the humps from the overlapping to deal with. Would pouring a layer of epoxy thickened w\ fairing compound (West Systems 410) across the whole floor be a good idea? My plan is to cover everything with a uniform layer of epoxy in a similar way to pouring self-leveling concrete. I also have something to sand into as opposed to the glass.
     
  2. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    All that laminate is dry. You need to grind it out and redo it. Epoxy won't fix the problem. It will delaminate.
     
  3. ElHurrecan
    Joined: May 2017
    Posts: 5
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    Location: USA

    ElHurrecan Junior Member

    Those pictures are not from my boat, they are from a restoration job that my friend is doing on a Boston whaler. I was just posting them because I was wondering if that's what the fiberglass should look like when cured (white\clear). I have not laid my glass yet for my boat.

    What's the issue with that fiberglass job and how can I avoid that? His application technique was to wet the glass base, lay the mat, then brush resin into the mat. He used a finroller to work out bubbles. I assume the fiberglass should have a clear appearance as opposed to white. Did he not use enough resin?
     
  4. jorgepease
    Joined: Feb 2012
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    Location: Florida

    jorgepease Senior Member

    either he didn't use enough resin or it was a porous surface and it got absorbed whatever happened, avoid that. You can spread the resin with a plastic squeegee board, much faster than a roller which can tend to pull up on the glass and might also pull out some resin but adding a peel ply and rolling over that in the end works pretty well.
     
  5. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    That is bad, it didn't get absorbed, he just didn't wet out the glass, looks like he put the glass down and then tried to force epoxy through the glass, it's hard enough to do it on thin cloth with no mat, it's very difficult when you add mat to the mix.

    Always put a good deal of epoxy on the surface before you lay the glass down, then work it up through the glass, add more to the top Side as needed.
     

  6. redreuben
    Joined: Jan 2009
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    Location: Beaconsfield Western Australia

    redreuben redreuben

    It’s too symmetrical, I don’t think it’s a dry laminate, I think it has been ground back to the coremat reinforcement perhaps ?
     
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