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Straightening bowed plywood ???

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  • Straightening bowed plywood ???

    Sometimes you just can't find plywood that is flat. I've tried putting the bowed plywood on blocks and putting weights on the center to bow it in the opposite direction but that doesn't seem to work well.

    What is the best way to correct this problem?


  • #2
    Re: Straightening bowed plywood ???

    Well, I have never found a way. But when I can buy them and they are flat, I will never store them laying flat, always keep them on edge. If you can use that sheet for a smaller project, do so and go get another sheet. I'm sure they'll be others disagreeing with me, so lets see what they have to say....
    Great Link for a Construction Owner/Tradesmen, and just say Garager sent you....

    A good climbing rope will last you 3 to 5 years, a bad climbing rope will last you a life time !!!


    • #3
      Re: Straightening bowed plywood ???

      If you have a concrete garage floor, lay it on the floor with the cupped side down. As it absorbs the moisture from the concrete, it will straighten some. If it is thin (i.e. 1/4"), spritz some water on the cupped side. As it absorbs the water, that side will expand and straighten it some. After it straightens (if it does) store it on end where air can get to both sides to store, or stack and put plastic over the outside surfaces. I have had limited success with these methods. The idea is to not have one surface get exposed to more moisture than the other once it is straight.
      Neither method is guaranteed, and as we get more offshore ply, it appears less of the wood in the plies is dried properly first, and the boards are stacked and banded immediately. When released from the bands, each ply returns to its natural size, resulting in some of the potato-chip looking junk you see in the borg. For those, I don't know as there is any cure.
      For furniture ply, if I only have one or two sheets, I either let them stand on end with spacers in between for a few days in the shop to acclimate both sides, or I cut to rough size, stack and cover. After I finsh cut, I either assemble or again stack and cover. I try to get a finish on both sides as soon as possible after glue-up.
      The cheaper quality the ply, the worse the problem will be

      That's been my experience
      Good luck


      PS If you are using CDX or BC ply, just use a lot of support and fasteners. There is no stopping the warp.
      Practicing at practical wood working