I’m building a table with live edge slabs. It’s going to be 3 slabs wide. They’re white oak about 16” wide each and I cut them down to 6’ long. I had them standing up in my garage for quite about 8 months. Before that they were cut and dried for about 4 years. I have 2’issues I’m trying to solve. One is the boards have started cupping a little. Some spots are bad (about a 1/2” difference). I was thinking of renting a floor sander to flatten these out since I don’t have a commercial planer or drum sander. Any thoughts on that? My biggest issue though is one of the boards is pretty twisted. When on a flat surface, the one corner is raised by about a 1/2”. What’s the best way to fix the twisted slab and get it flat?