New to this, plywood question

Discussion in 'Wooden Boat Building and Restoration' started by juan manuel luna, Feb 15, 2019.

  1. juan manuel luna
    Joined: Feb 2019
    Posts: 4
    Likes: 0, Points: 1
    Location: Argentina

    juan manuel luna New Member

    Hello! My name is Juan Manuel Luna, I'm from Argentina. I'm going to build a stitch and glue boat. Easy build for my first motor boat. The boat is a classic 17, c17, from bateau. I know almost everything about stitch and glue build, but I have a question. I can't find okoume marine plywood in my country. I could only find marine pine plywood. I know, is not the best. But for know is what a have. What do you think about that plywood?. My idea is to go practicing and lerning for more complicated and bigger boats. So any idea or opinion is welcome. Thanks for all!
     
  2. Mr Efficiency
    Joined: Oct 2010
    Posts: 7,570
    Likes: 244, Points: 63, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    "marine pine plywood". If it is certified as "marine", which would mean waterproof glue, no knots etc, it may be quite OK, pine is a very generic term, could mean anything. Some pine species are used in marine plywood.
     
  3. rwatson
    Joined: Aug 2007
    Posts: 5,822
    Likes: 270, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    Sounds like a good plan. Bateau does a good job with their plans and help, I have found.

    IF the plywood is marine grade, that is a good start.

    The type of pine, you haven't said.

    I presume the whole boat will be encapsulated in Epoxy, so the quality of the wood to withstand water isn't as critical.
    BUT
    If the plywood is oily or "sticky", there might be issues with Epoxy adhesion. This is particularly a problem with Radiata Pine timber.
    You need to do a test if you have any doubt. Just get a small piece, and apply some epoxy and glass, and see how well it adhere when cured. .25 m squared would be sufficient area for a test.

    The next biggest issue would be weight. You don't want an overweight boat, but at 17ft long, its not going to be as critical as a smaller boat like a canoe.

    So adhesion and weight are the two things to look into.
     
  4. Angélique
    Joined: Feb 2009
    Posts: 3,005
    Likes: 317, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Last edited: Feb 17, 2019
    rwatson likes this.
  5. missinginaction
    Joined: Aug 2007
    Posts: 744
    Likes: 63, Points: 28, Legacy Rep: 512
    Location: New York

    missinginaction Senior Member

    In response to Rwatsons comment about Radiata Pine. Maybe we're not talking about the same thing but I used a product called AraucoPly. I'll post a link to the manufacturer below.

    http://web.araucoply.com/informacion2.asp?Submenu=1514&cat=0&fin=0&idioma=44

    I didn't build a hull out of it. I did use it for the interior cabin sole, interior partitions and most importantly the flybridge on my 1973 Silverton restoration. The flybridge was built in 2012, the other parts somewhat earlier. I used the sealing methods that I learned here. Three coats of resin on all 6 sides and then sheathed the panels with 4 oz. fiberglass cloth, they were prepped and painted with 2 part LPU paint and the interior panels were sometimes done with HPDL (Wilsonart). I'm meticulous when dealing with fasteners and sealing. I never had a problem with any of it, the boat has been in use since 2014 and sits at the dock all summer. That flybridge, especially, is sitting out drenched in dew every night and baking in the sun all day.

    It's somewhat heavier than Okoume but other than that it's performance was fine. I don't think I'd build a large hull out of it but for what the OP wants to do it may be an option.

    The OP should be able to find AraucoPly in his country as I understand that it's actually made there. Before I started with AraucoPly I boiled it in a pot for a few hours then baked it in an oven then boiled it again. It never delaminated.

    MIA.
     
    fallguy and Angélique like this.
  6. Angélique
    Joined: Feb 2009
    Posts: 3,005
    Likes: 317, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    I've just looked at Vendia plywood products made of Finnish pine, from the above article. Which is made from sliced rather than rotary peeled veneers, so it's only available as planks and beams, and not as sheets. Keel beams and keel planks and bent frames (don't know about the curves) and gunwales are made of only lengthwise grain veneers. It looks good to me for any kind of planking and beams. The main disadvantages seems to be no sheets available, and at 600~700 kg/m³ it's almost twice as heavy as Okoume plywood of 330~410 kg/m³ at 12 % humidity. Maybe Vendia ply is stronger and can do with thinner scantlings . . ? ?

    Example; 9 mm thick Vendia Pro plank. Widths: 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425 mm. Lengths: 2600 and 3000 mm.

    ‘‘ Face veneers are made of knot-free pine and core veneers of pine. VENDIA Pro consists of eight veneer layers in total: six lengthwise veneers and two crosswise veneers. Face veneer thickness is 1.5 mm (× 2 = 3 mm) and core veneer 1.2 mm (× 4 = 4.8 mm). Cross veneers are 0.6 mm (× 2 = 1.2 mm) thick. This structure increases the longitudinal stiffness of the plank and it meets the longitudinal stiffness of 12 mm solid plank. This product is developed with a boatbuilder for experienced boatbuilders. ’’

    [​IMG]
     
    Last edited: Feb 19, 2019
  7. Angélique
    Joined: Feb 2009
    Posts: 3,005
    Likes: 317, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    That seems to be a good test. The only mistake I've seen in the above horror story is that they've painted it dark blue, which makes it far hotter in the sun than white, but that shouldn't cause that kind of problems.
     
    Last edited: Feb 18, 2019
  8. Mr Efficiency
    Joined: Oct 2010
    Posts: 7,570
    Likes: 244, Points: 63, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    What rwatson calls Radiata Pine, would be better known to some as Monterey Pine. The AraucoPly sounds, from the name, like it would be derived from the Araucaria genus of pines, but I notice it is described on the website as being from plantation Radiata, a Pinus species ! In Australia, the local marine ply is commonly made from Hoop Pine, Araucaria cunninghamii.
     
  9. rwatson
    Joined: Aug 2007
    Posts: 5,822
    Likes: 270, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

  10. Mr Efficiency
    Joined: Oct 2010
    Posts: 7,570
    Likes: 244, Points: 63, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    There are actually Araucaria species native to South America, like the Monkey Puzzle Pine, which has a strong resemblance to the Australian Bunya Pine. Courtesy of the ancient "Gondwanaland" splitting eons ago. Monkey Puzzle Pine top picture.
    Monkey Pine .jpg


    Bunya.jpg
     
  11. juan manuel luna
    Joined: Feb 2019
    Posts: 4
    Likes: 0, Points: 1
    Location: Argentina

    juan manuel luna New Member

    Hello! thanks for the reply! I read all the comments!. I could only find virola marine plywood, they say is similar to luan and mohagany. What do you think? thanks!
     
  12. fallguy
    Joined: Dec 2016
    Posts: 1,902
    Likes: 105, Points: 63, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Boil test.

    It is that simple.
     
  13. Yellowjacket
    Joined: May 2009
    Posts: 596
    Likes: 82, Points: 28, Legacy Rep: 447
    Location: Landlocked...

    Yellowjacket Senior Member

    If the glue is good quality marine glue the ply's won't delaminate if it gets wet, but the real issue will be that after a while it will tend to check if you don't put a layer of deck cloth (40z) glass over it... If you glass it, even with a light layer of cloth it'll be fine.
     
    BlueBell likes this.
  14. Angélique
    Joined: Feb 2009
    Posts: 3,005
    Likes: 317, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    If the glue is of good marine quality, and if it's processed correctly, with wood of the right humidity degree, are things the consumer doesn't know without testing.

    Best ask for a sample beforehand and test it as per post #5 and #12, and when buying then best test also a sample of each batch and thickness you get, and return it when not good.
     
    Last edited: Feb 21, 2019

  15. Angélique
    Joined: Feb 2009
    Posts: 3,005
    Likes: 317, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Of which brand, and what are the full specs . . ? - If you post that here then we can discuss it here, and best also ask the designer of your boat.
     
    BlueBell likes this.
Loading...
Similar Threads
  1. abosely
    Replies:
    44
    Views:
    5,550
  2. sab
    Replies:
    40
    Views:
    5,037
  3. Paul_A
    Replies:
    30
    Views:
    7,084
  4. armstpat
    Replies:
    29
    Views:
    4,105
  5. Wolfgang123
    Replies:
    29
    Views:
    5,563
  6. john mac
    Replies:
    23
    Views:
    2,876
  7. Elmo
    Replies:
    9
    Views:
    3,929
  8. freeboatrsrce
    Replies:
    4
    Views:
    1,491
  9. erik818
    Replies:
    17
    Views:
    6,992
  10. unseen wombat
    Replies:
    23
    Views:
    6,927
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.