Hull fairing questions

Discussion in 'Boatbuilding' started by laukejas, Nov 2, 2020.

  1. fallguy
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    fallguy Senior Member

    Oh, had my share of painting fun. But I would never paint over raw epoxy. The fairing gets harder and harder to do without color change.
     
  2. laukejas
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    laukejas Senior Member

    Okay guys, thank you very much for clarification. I imagined that primer is much closer to filler than it is to paint. So if I were to use a proper primer, and noticed some surface defects that needed to be filled, I understand that I would be using filler epoxy there, not more primer, correct? If so, then I suppose there is no other kind of primer that could happily sit between different coats of filler epoxy without delaminating afterwards?
     
  3. fallguy
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    fallguy Senior Member

    yup...epoxy primer...epoxy filler
     
  4. wet feet
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    wet feet Senior Member

    You could use those small test pieces for experimenting.
     
  5. laukejas
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    laukejas Senior Member

    Well, crap. I guess there is no way around this. Guess I'm stuck. One of my epoxy suppliers wrote me back just now (I sent inquiries about epoxy primer to 5 suppliers that I have here in Lithuania). This was the only one that wrote they have epoxy primer available. Price is $364 a gallon. Yeah, that is not a typo. Compare that to regular epoxy that is ~$50 a gallon around here...

    Okay, I will keep searching. I have taken enough of your time already. Thank you very much for all the information, I really appreciate it.
     
  6. fallguy
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    fallguy Senior Member

    Epoxy primer costs about 100-200 a gallon here or say $50 a liter.

    More than that is the markup game.
     
  7. Blueknarr
    Joined: Aug 2017
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    Blueknarr Senior Member

    That isn't an unusual price.

    I've seen it retail for $85/ quart in California

    All depends on your final finish appearance expectations. Do you want the perfect 10 found on multi-million dollar mega-yachts? Or a 1 done by a toddler using finger painting?

    Home brew epoxy fairing compound can be 250 mils thick with 10 mill deep defects common

    Quality high build primers can be applied to 50-150 mills Dry Film Thickness. They usually sand to less than 1 mill deep imperfections.

    High end marine or automotive paints are 2-4 mills dft.

    Quality oil based paints 5-10 mills dft

    If a level 8.5 finish is acceptable,
    Then half a dozen coats of oil paint will suffice.

    If that elusive 10 is the target,
    Then expensive primers orA hundred coats of two-part paint with be required.

    The toddler doesn't care if it's cheep or expensive paint
    As long as it is a pretty color

    Your not waisting any of my time
     
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  8. fallguy
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    fallguy Senior Member

    Acrylic enamel oil work underwater?
     
  9. Blueknarr
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    Blueknarr Senior Member

    Probably yes
    For intermittent submersion. If it is a true oil. Or thins and cleans up with solvents

    Some acrilic is oil "fortified". It is crap on a stick. Don't use it under water at all! It thins and is claimed to clean up with soap and water but doesn't. Solvents won't clean it out of a brush either.
     

  10. fallguy
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    fallguy Senior Member

    Those narrowboats in merry old England use oil somethings iirc.
     
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