I made this rib straightning tool to make this process really easy. There are several versions you can make if do a search on VAF or google. I found a strap hinge at Lowes I liked due to the hole pattern being in a straight line. It was easy to make and works great. The angle on the 2X4 is 11 degrees and after pressing the flange it springs back to 90 degrees. Be careful not to straighten the end flanges on some of the ribs because they have been pre-bent to a certain angle. Example HS-00005.
