Fiberglass coating options - regular bonding primer?

Discussion in 'Materials' started by mvoltin, Dec 5, 2017.

  1. mvoltin
    Joined: Nov 2017
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    Location: ALABAMA

    mvoltin Junior Member

    Asking for a fiberglass coating options for something that will not be exposed to water:

    Building a large (23') model of spaceship to raise money for a school STEM program. The model will be mostly indoors and occasionally may be shown outdoors (DragonCon, etc.) and may accidentally get rained on but no extended exposure to water or adverse weather. The final look is supposed to be matte, thus it does not have to be perfect by any means.

    Part of the fiberglass (almost half) is done with polyester resin and the other is epoxy resin.
    Used the EverCoat Lite Weight fiberglass filler to smooth things out.

    Next steps:

    Initially, planned to use Evercoat Featherfill as a primer but it is expensive, difficult to apply and requires another primer on top before applying paint.

    Home depot has Kilz bonding primer that is supposed to bond to everything, including glass and tile. Will this work instead? it is both cheaper and easier to apply.

    And, if Kilz is acceptable option, what paint type of paint would you recommend? Or is there another option to cover the model.

    thank you.
  2. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    For your use; the main thing will be surface prep. You can't have shiny epoxy or ester finishes or risk peeling. The bonding primers are exceptional. Light sanding for the model would be best to avoid deep scratches. I'd say 120 grit which will minimize any deep scratches. However, there might be a few high build primers that might fill scratches better than the kilz; though would cost more. I like any primer that can be sanded and reapplied; so you might end up two primer coats for a 'model' finish.
  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Kilz will work fine. As fallguy says, prep is really important. Epoxy forms a wax on the surface after curing. Fortunately, it is water soluble, so you can wash it off with dish detergent and water.
    fallguy likes this.

  4. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    Your primer does not have to double as a filler, an acrylic undercoat on top of the primer can help that, and then finish with a low-sheen or matt acrylic colour coat. If the final coat is to be dark, you can tint the undercoat with some black tinter to make a grey. Much easier to cover than white.
    fallguy likes this.
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