Branding on plywood-need to remove?

Discussion in 'Boatbuilding' started by mariobrothers88, Jul 8, 2021.

  1. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,386
    Likes: 1,042, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Better to test all aspects, for sure
     
  2. gonzo
    Joined: Aug 2002
    Posts: 16,790
    Likes: 1,714, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    The plywood is marine grade, but made for forming concrete. The coating is to prevent adhesion, which is a problem if you want to bond anything to it.
     
    DogCavalry and DCockey like this.
  3. DogCavalry
    Joined: Sep 2019
    Posts: 3,078
    Likes: 1,572, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    Bizarre that they would make marine grade ply for form work.
     
    BlueBell likes this.
  4. fallguy
    Joined: Dec 2016
    Posts: 7,598
    Likes: 1,674, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Thanks Gonzo!! My main fear was bond problems with plastic. Epoxy will probably not bond to it and even if removed, a glue for the adhesion may be lower strength than a 2000 psi epoxy bond...
     
  5. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,386
    Likes: 1,042, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    As fallguy indicated, conduct a test of all aspects that concern you, allowing a reasonable cure time for any epoxy adhesion test
     
  6. fallguy
    Joined: Dec 2016
    Posts: 7,598
    Likes: 1,674, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Not after Gonzo's post. Forget about that concrete forming board rebranded as marine ply..
     
  7. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,386
    Likes: 1,042, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    You can still test it, you can't test for species durability I guess
     
  8. gonzo
    Joined: Aug 2002
    Posts: 16,790
    Likes: 1,714, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Not really. The plywood gets reused and usually stored outside in the weather. Marine plywood will have a longer service life.
     
  9. DogCavalry
    Joined: Sep 2019
    Posts: 3,078
    Likes: 1,572, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    Excellent point.
     
  10. mariobrothers88
    Joined: Sep 2020
    Posts: 215
    Likes: 10, Points: 18
    Location: San Diego, CA

    mariobrothers88 Senior Member

    The black plastic on the Chinese marine plywood is very easy to remove with an electric planer so removing it is pretty trivial.
     
  11. mariobrothers88
    Joined: Sep 2020
    Posts: 215
    Likes: 10, Points: 18
    Location: San Diego, CA

    mariobrothers88 Senior Member

    Hi guys so I did a 1 hour hard boil test of the Canadian marine plywood (red) , Chinese consmos marine plywood (yellow) , Birch plywood (green) , and okoume marine plywood (blue) . Here are the before and after photos.

    It looks like the consmos Chinese faired the best although most of the black plastic melted off. All three marine grade plywoods survived the test only the Birch disintegrated.

    Based on this, I'm leaning towards the Chinese consmos brand and planing off the black plastic with an electric planer (very easy to remove). But what do you guys think? Would you still go with the Canadian marine ply?
     

    Attached Files:

  12. Blueknarr
    Joined: Aug 2017
    Posts: 1,449
    Likes: 412, Points: 83
    Location: Colorado

    Blueknarr Senior Member

    There would need to be an extreme price/availability difference to justify me using the cosmos. How must time and effort is it going to take to produce a surface that has uneven plainer tracks. How much more time and effort to rectify the plainer tracks?
     
    DogCavalry and fallguy like this.
  13. gonzo
    Joined: Aug 2002
    Posts: 16,790
    Likes: 1,714, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Planing plywood is a bad idea unless you are planning on laminating a relatively thick layer of fiberglass on each side.. The veneers are balanced; they are the same thickness and symmetrical.
     
    fallguy and Blueknarr like this.
  14. DogCavalry
    Joined: Sep 2019
    Posts: 3,078
    Likes: 1,572, Points: 113
    Location: Vancouver bc

    DogCavalry Senior Member

    Unless your time is worthless, the Canadian takes it.
     
    missinginaction and BlueBell like this.

  15. mariobrothers88
    Joined: Sep 2020
    Posts: 215
    Likes: 10, Points: 18
    Location: San Diego, CA

    mariobrothers88 Senior Member

    Hi guys so I met the actual owner of the hardware store and he told me that the consmos plywood is NOT marine grade (despite what his workers told me)! I already used it to fabricate the outboard motor mount which I spent a lot of time on already so it seems like a big waste to just throw it away and redo it with the Canadian plywood. I was thinking of using it but covering it with a veneer of 6mm marine grade plywood to protect it from the elements. Do you guys think that would work or just redo it with the Canadian marine plywood?
     
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.