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Is there a way to unwarp a piece of 20 x 20" piece of 1/8" inch thick piece of plywood?

I trying wetting one side and weighing it down with weights.

https://www.dropbox.com/s/e69r6iecj5farjj/20180820_123605.jpg?dl=0

  • There's quite a bit of related info in existing Q&As already, which pretty much covers the topic. See the Related column to the right --> – Graphus Aug 19 '18 at 17:29
  • I checked some out. Steam bending, scrapping the wood, etc is not practical as I have a limited budget. – fixit7 Aug 19 '18 at 18:27
  • If you want to try damp heat you can do this without any expenditure, you can steam over a boiling kettle, hot damp cloths laid on the wood (damp, not dripping wet) and even dampening the plywood surface and carefully applying a hot iron. – Graphus Aug 20 '18 at 12:41
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    What is your use for this material? Normally something 1/8" thick wouldn't be expected to be used in a situation without some kind of frame or backing (unless it's in a very small piece). It's just too thin to support itself and stay stable. – SaSSafraS1232 Aug 20 '18 at 15:07
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    I do not understand "the more that is left". I want to put some hinges on the plywood so it can swing out. The plywood has a very nice grain pattern. I may buy a thicker piece of plywood that is not warped and glue it to the back. What do you think? – fixit7 Aug 20 '18 at 17:30
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Unless this board holds special value to you, any big box store will have a 4x8' sheet of 1/8" hardboard for $5-$10. If they're not too busy they'll cut it while you wait.

That said, if I was determined to work with what I've got, I'd try to reverse the warp:

Like the underside of a shriveling leaf, the plywood’s concave side has lost moisture and shrunk. Reversing the warp can be accomplished by adding moisture to this concave side and drying the convex humped side. I use a sponge or sprayer to wet the concave side of the plywood (hot water works best). Then I lay the sheet, moist side down, on a shop floor or a driveway. Now the sun, or the warm interior air, helps to dry out the convex, humped side of the plywood. At the same time, moisture is being absorbed into the concave side. This process works faster than you can imagine, so keep an eye on the material. If it warps the other way, just reverse the process.

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  • Nice answer, but: "concave side?" The whole thing is concave. To which side are you referring? – 3Dave Aug 23 '18 at 21:08
  • @3Dave if you're looking at a warped board and it looks like a 'U' or a bowl, you have the concave face up. if it looks like an 'n' or a hill you have the convex face up. you want to wet the entire concave face and let it dry in the sun with that side face down – Rob Elliott Aug 24 '18 at 15:55
  • Ahhh... that makes sense. And seems obvious in retrospect. :/ – 3Dave Aug 24 '18 at 17:32

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