





How to keep massive oak slab from warping/how to fix it?
So I have this giant slab of oak that I’ve been working on. It has two trees which grew into one, and then maybe a little tiny tree right above the right core. A few weeks ago, I built a jig and used a router to plane it flat and it worked after some trial and error (had never used one before) I took a level to it and it was perfect so I worked on the sides then set the slab to the side for a few weeks to work on something else. It was left sitting flat on the table with nothing under it (picture 2) and here you can see how underneath the slab on the right I didn’t completely plane it because it be on the underside of the table. Yesterday, I started sanding it and when I flipped it I noticed how warped it had become (picture 1). Pictures 4, 5 and 6 show the level after it warped, which to me it seems like the middle sunk in somehow.
What do I do? Is there any way to fix the warping without having to plane it again? Is there some kind of support or groove that needs to be added to prevent this? Is it doomed to forever warp? I have very little experience with woodworking so absolutely any advice is greatly appreciated.