The corner panel had a slight flat stamped area in the middle of it. It's easy to lose these details if you don't use guidecoat and block these areas specifically. I started by blocking the flat area by itself, watching the guidecoat until I knew it was flat top to bottom. I wasn't worried about the edges being uneven, that's for the next step.
Next I re-guidecoated the center flat spot, and started blocking the right side, taking care to evenly block up against the flat area- again using a "X" blocking patter 45 degrees to the edge of the flat spot. Watch the guidecoat to see when the edge against the flat spot become straight.
And repeated on the left side.
Once both rounded sides were done, I shot more guidecoat on the sides and re-blocked the center flat area with 180 grit to double check for straight edges. Using 180 slows the cut of the block so you can slowly work up to getting the edges dead even. The edges of the flat area are now dead straight.
