Help Identifying Plywood

Discussion in 'Materials' started by Charlyipad, Dec 9, 2018.

  1. Charlyipad
    Joined: May 2014
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    Location: St Simons is ga

    Charlyipad Senior Member

    I need to find some numbers (bending modulus etc) for this plywood. I bought it about five years ago here in Georgia. My supplier has been of limited help in finding the origin, species, mill, etc. I plan to try with them again tomorrow, but in the meantime, is there anything obvious you could tell me from the photos? It was stamped Marine grade and appears to be fir. The glue is dark colored, you can see it in the pic with the bevels cut into the stack for scarfing. Thanks!
     

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    Last edited: Dec 9, 2018
  2. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Testing is the only way.

    How thick is that stuff?

    A two or three inch thick piece of ply isn't that common. If you can't find the mill; you might get some better ideas by explaining the thickness of each layer for an estimate from someone here. But it will be an estimate.
     
  3. Charlyipad
    Joined: May 2014
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    Location: St Simons is ga

    Charlyipad Senior Member

    Hi fallguy, It is only 1/2 inch. The second photo shows a stack of several sheets that I laid out and beveled together with a grinder and longboard in prep for joining scarfs. I posted it so you could see the glue joints clearly. The glue is a dark brown and I don't know how to identify glue. Is is phenolic, you think? I am going to the yard where I bought it tomorrow and photograph the edge stamps or any other identifiers I can find. Anything in particular I should look for? It is a reputable lumber yard, though they only carry one brand of marine ply; this is it. I think it has five plies. Thanks.
     
  4. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Best to find it from the source.

    If you are nervous about the plywood; you can boil test it, too.
     
  5. SamSam
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    Location: Coastal Georgia

    SamSam Senior Member

  6. Charlyipad
    Joined: May 2014
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    Location: St Simons is ga

    Charlyipad Senior Member

    Hi Sam! Thanks. I need the numbers so designer can do calcs for the bow beam. Probably will wind up having to get it tested. There is a place down in Melborne Fla I think that does it. Do you know of anyplace closer? Just curious about the glue. Hope you are well.
     
  7. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    Thanks. Maybe it would be easier and less expensive to just buy new stuff that has all the certs with it, or possibly use what you have but use more of it and overbuild it. I suppose you have to jump through flaming documentation hoops for chartering though. Are you still living in the same place? I think I remember you were going North for chartering.
     
  8. Charlyipad
    Joined: May 2014
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    Location: St Simons is ga

    Charlyipad Senior Member

    still here will be back at morningstar in march 19
     

  9. Deering
    Joined: Feb 2005
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    Location: Juneau, Alaska

    Deering Senior Member

    It certainly looks like Douglas fir, but if it was milled in Georgia it could be something else. I don’t think fir grows around there. The only marine grade plywood standard I’m familiar with is the British BS 1088 standard. Not sure if it’s relevant to your wood - might only apply to tropical hardwoods - but look for a good sized red ink stamp on the face that has BS 1088 in it. Probably won’t give you all of the data you’re looking for but it’s a good start. I would expect that the glue is an exterior grade plywood phenolic compound.
     
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