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I am into wood working field for for past few years only thing I am always wrong in assessing the quality of the plywood. I mostly get warping of my boards after the pasting of laminates. Can someone get me good tips for finding the good quality of the plywood.

  • Hi, welcome to StackExchange. If you're bonding laminates to plywood you may not be having a problem with the quality of the ply, it may be a problem of technique. When you stick laminate to the face of a board you're supposed to add something to the other side as well, a process referred to as counter veneering. This equalises the stresses that occur from the drying glue layer. Where this happens on one face only there's a very good chance the board (no matter the material) will warp in some way. – Graphus Jan 1 at 7:43
  • Thanks for your info... That's quite a new information and it is useful to me..... So your point is we need to do counter veneering, But even though we paste laminate on both side we see small warping sometimes... Is there any other things that has to be noted to avoid warping. – nivash-IoT Jan 1 at 15:23
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    Plywood plies alternate direction. Verify that the veneer direction is perpendicular to the plywood and that the grain for the counter veneer is in the same direction as the veneer itself. – Ashlar Jan 1 at 17:50
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    I do not know of a video, but should be able to explain it. Plywood always has an odd number of wood layers glued together. The wood layers are obtained by taking a tree, placing it on a spindle, rotating the trunk against the blade, and shaving a continuous sheet of wood the thickness of one layer of the plywood (a single ply). Once the sheets have been dried, the individual sheets are glued together in layers. If all the layers were run with the grain running in the same direction, the composite plywood sheet would only be strong in the direction of the wood grain.... – Ashlar Jan 2 at 3:26
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    ...So instead, the grain of alternating layers are rotated 90 degrees so that the plywood will be strong in both the long and short directions of the final sheets. There are always an odd number of layers so that the stresses are balanced. When you add another veneer layer to one side you are creating two layers that want to curl along the same direction. It is better to balance that stress with a counter veneer layer on the opposite side. Orienting the new layer's grain perpendicular to the previous layer also helps balance the stresses in the panel – Ashlar Jan 2 at 3:29

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