Epoxy/Fiberglass over Enamel Paint?

Discussion in 'Materials' started by SimoBoat, Oct 1, 2017.

  1. SimoBoat
    Joined: Oct 2017
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    Location: Minnesota

    SimoBoat New Member

    Can I epoxy over plywood painted with Rustoleum enamel to help waterproof my hull's interior?

    Recently built one of Spira's Pacific Power Dories. I fiberglassed the hull's exterior but only painted the hull's interior with Rustoleum exterior enamel (I was originally just looking for cheap way to get out on the water but turns out I am using the boat more than expected). I would like to be able to go out on rainy days. Can I just epoxy/fiberglass over the interior or do I need to sand off the Rustoleum? Is there something else recommended to waterproof the interior?

    Thanks for the advice.
  2. waikikin
    Joined: Jan 2006
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    Location: Australia

    waikikin Senior Member

    I'd just park it so the transom drain drains...
    Until next you use it- ventilation and drainage is the key to longevity.
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcome to the forum.

    Water proofing is only as good, as the coatings is, at being waterproof. Paint isn't, so it has to go, if you expect the underlying wood to get waterproofed.

    Agreed this isn't absolutely necessary, but is a generally accepted practice. Keep it clean, dry and in good maintenance and you'll likely be fine.
  4. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    I don't know what that paint is , either an alkyd or polyurethane by the sounds, but stripping it off to start again with epoxy sounds an awful chore. Whilst not waterproof, that paint if kept regularly re-painted, should offer good protection though, after all there are 100 year old timber houses still in good condition, even pine, and nothing more than paint films protecting it. And to continue the analogy, it is where water lies and pools, that the rot, literally, sets in, for example on step treads, so as waikikin says, keep it well-drained.
  5. SimoBoat
    Joined: Oct 2017
    Posts: 2
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    Location: Minnesota

    SimoBoat New Member

    I appreciate the quick responses.
    Originally, I thought I would only use the boat once in a while on sunny/calm days. But I got addicted to fishing and the joy of using your own boat makes me want to take it out rain or shine.

    Since I only intend the boat to last 3-4 years and its kept in a garage (I would already be building boat #2 if I had the time) - I think I'll just add some extra layers enamel - or maybe exterior poly.

    Thank You,

  6. pauloman
    Joined: Jun 2010
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    Location: New Hampshire

    pauloman Epoxy Vendor

    yes if the paint is well bonded you can epoxy right over it. You'll need to paint the epoxy too as it doesn't like sun exposure.
    Best to use an epoxy that is more flexible than 'regular' marine epoxy

    paul oman - progressive epoxy polymers inc
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