I just tried resawing for the first time and had a pretty big issue. I started out with a nice straight (no cupping, no bowing) 5/4 Walnut board about 7 inches wide and 6ft long. I resawed it in half so I'd have two boards about 1/2 inch thick. After resawing both boards have a huge bow in them. If I stand them back up together (with the resawed faces together) the are together at the ends but in the middle there is like a 1/2" to 3/4" gap. In fact, the force of them pulling apart was so string that when I got to the end of the board while resawing it just snapped apart while I was sawing.
What is the issue here? Is there something I'm doing wrong? Am I buying the wrong lumber? Did I just get a bad board?
I bought it at a good lumber supply, and used a 14" Delux Rikon with a 3/4" timberwolf resaw blade if any of that metters.