Hull fairing questions

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

  1. fallguy
    Joined: Dec 2016
    Posts: 3,849
    Likes: 579, Points: 123, Legacy Rep: 10
    Location: usa

    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
    Joined: Feb 2012
    Posts: 738
    Likes: 17, Points: 18, Legacy Rep: 128
    Location: Lithuania

    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
    Joined: Dec 2016
    Posts: 3,849
    Likes: 579, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    yup...epoxy primer...epoxy filler
     
  4. wet feet
    Joined: Nov 2004
    Posts: 570
    Likes: 56, Points: 28, Legacy Rep: 124
    Location: East Anglia,England

    wet feet Senior Member

    You could use those small test pieces for experimenting.
     
  5. laukejas
    Joined: Feb 2012
    Posts: 738
    Likes: 17, Points: 18, Legacy Rep: 128
    Location: Lithuania

    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
    Joined: Dec 2016
    Posts: 3,849
    Likes: 579, Points: 123, Legacy Rep: 10
    Location: usa

    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
    Posts: 1,019
    Likes: 216, Points: 63
    Location: Colorado

    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
     
    fallguy likes this.
  8. fallguy
    Joined: Dec 2016
    Posts: 3,849
    Likes: 579, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Acrylic enamel oil work underwater?
     
  9. Blueknarr
    Joined: Aug 2017
    Posts: 1,019
    Likes: 216, Points: 63
    Location: Colorado

    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
    Joined: Dec 2016
    Posts: 3,849
    Likes: 579, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Those narrowboats in merry old England use oil somethings iirc.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.