Fixing warped oak panel

[AwesomeOpossum74]

I'm making a lid for a d&d (dungeons and dragons) player box. I bought the wood from my local big box store. I've been back to the store (and others) multiple times to see if they have any better wood and all of it is warped.

Is there any way to unwarp this piece permanently?

[JGrout]

yes do not depend on retail stock to be flat 

Mill the stock flat yourself  handplanes jointers routers are all options for flattening stock 

The piece you have once ripped to width may be flatter than it is right now 

the key is to understand that depending on someone else is an effort in futility 

Joe

[Steve N]

I think that was Joe saying if you want it done right, do it yourself.


Unfortunately starting with the thin piece doesn't give you any wiggle room to end up with a usable piece of stock. So start thicker and work it down evenly from both faces to where you want it, and you'll see a better piece of wood. The places that produce stock like that are serving people only concerned with a size, which likely is going to get nailed or screwed down, so they don't worry about the shape it will try to become if left alone.

[MichaelMouse]

There's a way to flatten it for current RH, but it's still possible it will move enough to look bad later.  Find stock that is almost or fully quarter sawn to help your case

[TomFromStLouis]

This is the reason woodworkers end up with a garage full of tools. It is difficult to do woodworking half way like you can get away with doing, say, simple carpentry. You will want to shape each and every side of each and every board. This explains why most of us (I think) prefer to start with thicker rough sawn stock, but of course we already have the garage full of tools.

As mentioned, a thinner board that width will always want to cup a little bit with ambient moisture changes so a quartersawn piece that does not move those ways is suggested. Or design a lid that captures the thinner panel inside a frame strong enough to tame the tendency.

[AwesomeOpossum74]

A planer has been on my "wants" list for some time. But dang it, this should be a simple piece to make. Oh well, I may consider a different way to finish this project. Maybe a nice piece of Plexi glass, as the purpose isn't to hide the contents.

[jppierson]

If you have enough width, rip the panel, joint the two halves with the show side together using your hand plane, re-glue.

[JGrout]

A planer has been on my "wants" list for some time.  But dang it, this should be a simple piece to make.  Oh well, I may consider a different way to finish this project.  Maybe a nice piece of Plexi glass, as the purpose isn't to hide the contents.

A planer does not especially fix the issue you have 

planers make stock parallel face to face provided you have a flat reference to start with

You do not 

Joe

[BobW]

Throw the board on some damp grass in the sun, concave side down.  Keep tabs on it, and when it has straightened out, bring it inside and get a finish on both sides to seal it before it warps again.  I used to do this with parts from antique furniture that had warped...worked every time (but if it doesn't, you haven't lost anything).