I don’t know of many woodworkers who set out to have their glued-up panels warp. Warped panels happen to most of us at one time or another. It is reason to question your procedure and if you did something not quite right. Were your pieces dry? Did you allow the wood to reach equilibrium in your shop before milling? Did the humidity in your shop change between the time you glued your panels to when you got back to working them? These could all be contributing factors as to why you experience warped panels.
What warped panels are not is a reason to be yanked off or disturbed. There are ways to work with warped panels short of cutting them in half and re-gluing. That’s good news if your panel is already sized to final dimensions.
If your panels are slightly warped, I say push on, especially if there are to become case sides trapped in mortises. And if they are raised panels locked in a frame, why fret. Keep plowing ahead.
Straighten Before Tenons
In my case my panel gained a small bow located at about the middle of the part. Without flattening the panels, which couldn’t be done with hand pressure, my tenons would cut straight but the fit of the tenons into my mortises would have been crap. I turned to my shop-made fence extension – it hooks over my table saw fence with a fit that is tight enough to stay put as I push panels over the blade, or it slides easily if I clamp to the extension.
In the above photo you can see I’m using a single wood-screw placed near the center to take the bow out of the panel. When you flip the panel it’s tight to the fence in the middle, but away from the fence at both ends. To pull the panel flat in the scenario, use two clamps as shown below. A little shop smarts and a good jig go a long way to getting results.
Here’s another look at my fence extension from the back side. Super easy to make – works great!